Antimicrobial use surveillance data need to be analyzed and reported in a standardized and harmonized way. In veterinary medicine, one approach is to use defined daily doses (DDD) for animals. DDD for animals are technical standards used in various measures or metrics that quantify antimicrobial use. The European Medicines Agency published principles for assigning DDDvet values based on information on dosing obtained from nine European countries. For measuring antimicrobial use in livestock within Canada, DDDs for animals reflective of Canadian veterinary antimicrobial use (DDDvetCAs) were needed. Our objectives were (1) to describe the development of DDDvetCA standards for pigs and poultry (broiler chickens and turkeys) for authorized and compounded antimicrobial active ingredients used in Canada, including those used extra-label; and (2) to compare the DDDvetCAs with EMA's DDDvets, where possible. Species-specific DDDvetCAs were assigned based on the average of unique antimicrobial daily doses obtained from product information, stratified by route of administration and age indication (where applicable). The feed, water and bolus DDDvetCAs were compared to oral DDDvets, and injectable DDDvetCAs to parenteral DDDvets, that matched by antimicrobial active ingredient. Seventy-five DDDvetCAs were assigned for pigs; 51 for poultry. Seventeen injectable DDDvetCAs could be compared to 14 EMA's parenteral DDDvets and 53 feed, water, and bolus DDDvetCAs could be compared to 40 oral DDDvets. Feed and water DDDvetCAs were generally lower than EMA's oral DDDvets, although differences in methodology between Canada and Europe make comparisons challenging. The assignment of DDDvetCAs was a resource intensive and iterative process. EMA's published principles for assigning DDDvets were an invaluable source of information. The use of DDDvetCAs will reflect exposure of Canadian animals to antimicrobials, be useful for evaluating associations between use and resistance within Canada and provide information for risk assessment and stewardship policies. However, when reporting antimicrobial use data internationally, using the same DDD standards as other reporting countries will facilitate between country comparisons, although differences in which antimicrobial active ingredients are licensed between countries may create challenges. Future steps include assigning DDDvetCAs for other food animal species, such as cattle, veal, and farmed fish. Antimicrobials have an important role in food animal production. Their use to treat, control, and prevent infections plays a part in the sustainability of food animal production . HoweverFor these reasons, some countries conduct surveillance of antimicrobials used in animals –5. The PData gathered by AMU surveillance programs must be analyzed and reported in a standardized and harmonized way to draw conclusions that are as accurate as possible. In addition to monitoring trends in AMU, these data are needed to develop effective farm and veterinary interventions, inform antimicrobial stewardship, and to provide information for risk assessment.One approach for animal AMU analysis and reporting is to apply a defined daily dose (DDD) for animals. The DDD for animals is a technical unit of measurement developed by the European Medicines Agency's (EMA) European Surveillance of Veterinary Antimicrobial Consumption (ESVAC) project . ESVAC cThe creation (or assignment) of standardized DDD for animals involves determining an average dose for each AAI authorized for use in the species of interest by route of administration . The priAccounting for dose when analyzing and reporting AMU is important since dosing between antimicrobials varies. This variation in dose may be due to differences in mechanism of action, pharmaceutical formulations, and metabolism and distribution in the body . To demoIn 2015, the EMA published principles for assigning DDDvets  with theUsing the principles for assigning DDDvets published by EMA, CIPARS decided to develop Canadian DDD for animals (DDDvetCAs). The decision to develop DDDvetCAs was made because of expected differences in antimicrobials between Canada and other countries, including antimicrobials registered for use, antimicrobial doses, the number of unique doses for an antimicrobial, and indications for use. Standardized DDD for animals based on antimicrobials authorized for use in Canada were needed for the analysis of AMU within a Canadian context. The primary objective of this study was to develop DDDvetCAs for all antimicrobials authorized (or otherwise known to be used in an extra-label manner) for use in Canada, starting with pigs and poultry (including broiler chickens and turkeys). A secondary objective was to compare DDDvetCAs with EMA's DDDvets for both species.Principles for the assignment of defined daily doses for animals as guidance in the assignment of DDDvetCAs for pigs and poultry, with minor changes as required  was used to tabulate the unique daily doses for each AAI, regardless of indication. Doses were stratified by species and route of administration . While EMA chose to group oral routes of administration together, we chose to keep them in separate categories. Since product information for feed and water medications often include doses in units such as mg/kg feed or mg/L water, conversion to mg/kg body weight was required. To do so, these doses were multiplied by either the feed or water to weight conversion ratio , as per ESVAC . Also, iDue to heterogeneity in drug product information, decisions had to be made during the tabulation of product doses . If the The distribution of doses was examined by calculating the minimum, maximum, and median daily doses for each AAI, in addition to the mean daily dose. To compare the mean daily dose (DDDvetCA) to the median dose, a ratio was calculated using Equation (1).In addition to dose information, the Health Canada Category of the AAI was recorded . These cantimicrobial 1_antimicrobial 2, which is understood as the DDDvetCA for antimicrobial 1 when it is used in combination with antimicrobial 2. In a similar situation, long-acting injectable ceftiofur in pigs was assigned a separate DDDvetCA from conventional injectable ceftiofur as the daily dose between the two formulations differed . Finally, consistent with EMA guidelines  for each matching DDDvet by species and route of administration. Ratios of one (±10%) were considered equal. Ratios above 1.1 indicated the DDDvetCA was larger than DDDvet, while ratios below 0.9 indicated the DDDvetCA was smaller. Ratios above 1.5 and below 0.5, indicating a more than 50% disparity between the two values, were considered to indicate a substantial difference between the two standards.An examination of the distribution of daily AAI doses showed that, for poultry, doses often varied widely for a given AAI . An examThe distribution of antimicrobial products by route of administration is illustrated in in-ovo. No DDDvetCAs were assigned for poultry based on compounded product doses at this time , and which doses to use for the determination of the mean dose . These decisions were sometimes revisited with the acquisition of new information.Part of what made the DDDvetCA assignment resource intensive was the need for human resources to extract dose information from product information in the CVP and CMIB. At times, tracking down manufacturer and/or expert opinion was necessary where no licensed product dose information was available. Between 10 and 15 min were required to extract the required information from each product, provided the product information was comprehensive and clear. However, differences in the way product information and drug doses were written caused significant variation in the time needed to extract the information required. Some product information was clear and easy to understand, while others were more complex. Some products had doses for multiple indications, multiple species, or multiple routes of administration. For example, some water products included doses for individual animal dosing and for herd/flock dosing. The process became faster as familiarity with product information increased.The decision to exclude growth promotion doses from the assignment of DDDvetCAs was consistent with EMA's guidelines, as in the European Union, the use of antimicrobial products for growth promotion is not permitted, and as a result, EMA's DDDvets are based on treatment and prevention doses only . In CanaA departure from EMA's guidelines was the assignment of DDDvetCAs to AAIs used in an extra-label manner in the species of interest. Prescribing antimicrobials in an extra-label manner is legal for veterinarians in Canada, when no approved product for the species of interest exists . For theWe followed EMA's DDDvet guidelines for assigning separate DDDvetCAs to AAIs used in combination formulations, when their mean daily doses differed from single ingredient formulations . In contThe decision to use an average, or mean, daily dose to assign DDDvetCAs was also consistent with EMA's guidelines and with the DDD in human medicine , 10. WhiA major difference between DDDvetCAs and DDDvets is the stratification by routes of administration for products administered orally. EMA grouped the oral routes of administration together when assigning DDDvets, creating one category called oral , 12, whiCIPARS' method of assigning DDDvetCAs by using only unique AAI doses to calculate the mean daily dose also differed from EMA's guidelines . EMA's mAn example of yet another way of calculating the mean daily dose is Postma et al.'s  method oAnother difference between CIPARS', EMA's, and Postma et al.'s  methodolDefined daily dose methodology in human medicine deals with differences in dosing by age by incorporating the weight of a standard adult (70 kg) into the assignment of the DDD . As a reThere are many other reasons for the observed differences in DDD for animals between CIPARS and EMA, one of which is that EMA may have had a wider range of AAI doses to work with, due to the collection of AAI doses from nine European countries . HoweverThe findings from this project confirmed the need for national DDDvetCAs for Canada for a few reasons. One reason was the observation that the DDDvets did not cover all the AAIs used in veterinary medicine in Canada. Also, while drawing conclusions from differences between DDDvetCAs and DDDvets assigned to oral routes of administration is difficult due to issues previously discussed, the differences observed between injectable DDDvetCAs and parenteral DDDvets appear to confirm the need for DDDvetCA that reflect antimicrobial selection pressure in a Canadian context.The assigned DDDvetCAs have already been used by CIPARS for reporting farm-level surveillance data , 25. In However, when comparing AMU between countries, using country specific DDD for animals such as the DDDvetCAs, may not be appropriate, due to the same challenges we observed when comparing DDDvetCAs and DDDvets. Differences in methodology and in antimicrobials authorized for use, among other issues, means that when reporting AMU internationally, it would be preferable for all reporting countries to use a set of international DDD for animals assigned using a single methodology. Ideally, these international DDD for animals would be assigned from globally represented product doses. Hence, the objectives of the reporting, whether national or international, will determine the choice of whether to use country-specific or international DDD for animals.A limitation of the DDDvet methodology is that they are based on AAI doses from product information, which may not reflect the use of the AAI in practice , 10. WheThe DDDvetCAs will need to be reviewed periodically as product doses may change, new products may be registered, or older ones discontinued. Also, new indications for use may be added to product information and changes in approved species may occur. While a DDDvetCA may be subject to review in specific instances, the aim is for the assigned DDDvetCAs to remain stable over time. This stability over time will allow for AMU trends to be followed long-term without frequent changes that will complicate analyses and interpretation. Future revisions will be aided by the Microsoft Excel® 2010 spreadsheet designed and used for tabulation and calculation of the DDDvetCAs, which will function as a database. To make future revisions easier, the development of an automated product registration system to flag product dose changes or new products would be helpful.The study of AMU is essential, enabling the examination of the impact on animal and human health due to the extent, nature, and determinants of AMU, and due to the associations between AMU and AMR. The DDDvetCAs will be valuable in the study of AMU in Canada, and while the process of assigning DDDvetCAs for the first time was challenging and resource intensive, maintaining them will require fewer resources. EMA's published principles for assigning DDDvets were an invaluable source of guidance and information for the creation of DDDvetCAs . Future The datasets generated for this study are available on request to the corresponding author.All authors listed have made a substantial, direct and intellectual contribution to the work, and approved it for publication.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Surrogacy is an assisted reproduction-based approach in which the intended parents assign the gestation and birth to another woman called the surrogate mother. The drivers of surrogacy refer largely to infertility, medical conditions, same-sex couples' parenting, and cases of diversity regarding sexual identity and orientation. Surrogacy consists of a valid option for a variety of conditions or circumstances ranging from medical to social reasons. However, surrogacy may be associated with risks during the preimplantation, prenatal, and neonatal period. It became obvious during the exhaustive literature research that data on surrogacy and its association with factors specific to the IVF practice and the options available were not fully represented. Could it be that surrogacy management adds another level of complexity to the process from the ovarian stimulation, the subsequent IVF cycle, and the techniques employed within the IVF and the Genetic Laboratory to the fetal, perinatal, and neonatal period? This work emphasizes the risks associated with surrogacy with respect to the preimplantation embryo, the fetus, and the infant. Moreover, it further calls for larger studies reporting on surrogacy and comparing the surrogate management to that of the routine IVF patient in order to avoid suboptimal management of a surrogate cycle. This is of particular importance in light of the fact that the surrogate cycle may include not only the surrogate but also the egg donor, sperm donor, and the commissioning couple or single person. Over the last decades, infertility has become a matter that the majority of infertile couples choose to address. Surrogacy has revolutionized the standing options within the assisted reproduction field, enabling the gestation and birth of child by another woman—the surrogate mother—relinquishing the child after birth to the commissioning parents –3.The first type of surrogacy is the traditional (or genetic) surrogacy, in which the father's sperm or the donor's sperm is naturally or artificially employed to inseminate the surrogate's oocyte (homologous IVF). This approach leads to an embryo genetically linked to the surrogate. The second type is the gestational (or host) surrogacy. In this case the implanted embryo shares no genetic link with the surrogate mother. In gestational surrogacy, the embryo results from heterologous IVF employing the intended parents' gametes, or the intended father's sperm and donor's oocyte (not the surrogate's), or the donor's sperm and the intended mother's oocyte. Alternatively, the embryo could be donated –4.Infertility, medical conditions, diversities regarding sexual identity and orientation, and matters of social nature reflect the basic drivers behind patients' decision to pursue surrogacy. Women with a severe Müllerian anomaly or a congenital absence of uterus and/or vagina are usual candidates for surrogacy. The condition of Mayer-Rokitansky-Küster-Hauser Syndrome characterized by a female genotype and phenotype and accompanied with a congenital aplasia of the uterus and the vagina –7 represThe majority of surrogates report that the main incentive is altruism, as surrogacy reinforces their self-esteem, despite the fact that financial gain may also be a major consideration. In many countries, any payment to gestational carriers is legally prohibited, solely allowing some financial aid only for pregnancy-related expenses , 16. SpePrior to initiating procedures, certain factors should be investigated and valued to ascertain safe outcome for both the surrogate and the embryo. The surrogate should undergo medical examinations and thorough psychological assessment, in order to be considered suitable. The psychological assessment evaluates the surrogate's ability to emotionally sustain gestation and delivery. It has been reported that her status throughout the gestation could affect the child's individuality and psychological wellbeing . The ageTo date surrogacy may not present a straightforward alternative among women of reproductive age. In an interesting study, when presented with the option, women responded they would rather opt for uterus transplantation instead, with a percentage of 80% vs 47% . HoweverThis article highlights the challenges and considerations associated with surrogacy. It uniquely brings to literature the respective associations regarding the preimplantation embryo, the fetus, and the infant. When dealing with a surrogate cycle within the IVF set-up, is it possible that the urgency for the cycle, in order to secure an optimal result, compromises its management? Could these pregnancies, being widely characterized as “precious,” result in choices and practices that ensure the highest percentages of success? Extrapolating on that concept, could these choices be selected on nonmedical grounds and hence pose a risk? Is it possible that we lean towards a hyperbole when surrogacy is the case?Surrogacy goes hand in hand with IVF treatment and every aspect that this entails. A surrogacy cycle within the IVF set-up includes superovulation, oocyte retrieval, fertilization techniques, embryo culture, embryo selection, embryo transfer, and possibly cryopreservation. It is evident that surrogacy cycles require the services of IVF irrespectively of infertility etiology. The fact that these embryos are created within the IVF set-up may leave room for further manipulation of the embryo. Extended culture to the blastocyst level may represent a straightforward example as it may be believed to secure better implantation potential . FurtherBoth embryo manipulation and environmental factors within the IVF laboratory set-up may allow for epigenetic changes during the first stages of embryo development. Under epigenetic influence, the control of gene expression through DNA methylation, histone modification, and miRNA could be altered . These m peg1, kcnq1ot1, zac, and h19 [ peg1 gene and the methylation of h19—during the preimplantation period—are associated with superovulation, the patient's age, and the delayed oocyte maturation or if they were inherited, studies in human models reveal unclear conclusions. The imprinting defects involved may lead to clinical implications in ART, such as failure of the embryo to implant, spontaneous abortion, and/or fetal growth retardation attributed to dysfunctional placentas [Epigenetic changes could occur due to Exogenous Gonadotropins (EGs) exposition. EGs are administered to the ovary to a secure successful superovulation regime through controlled ovarian stimulation (COS). It has been proposed that EGs may contribute to epigenetic changes in four imprinted genes, and h19 , and may and h19 . The str and h19 . Therefolacentas . The datIn a surrogate cycle, aspiring to secure the highest fertilization rates, ICSI (Intracytoplasmic sperm injection) may be selected as the method of choice. On the grounds that fertilization results on ICSI are reported to be higher than standard IVF , 25, oftAiming to secure the highest implantation potential of embryos produced in an IVF laboratory and included in a surrogate cycle, it is common to opt for blastocyst culture. However, bypassing all the benefits associated with this practice , the hazIn the set-up of ART, transferring a euploid embryo to the surrogate mother is of paramount importance. This could ensure that the possibility of miscarriage, termination of pregnancy, or live birth related to a compatible with gestation disorder is minimized. In case of chromosomal abnormalities and/or monogenic disorders, Preimplantation Genetic Diagnosis and Screening (PGD/PGS) excavate monogenic diseases and chromosomal abnormalities, numerical or structural, leading to the best embryo selection , 19, 32.Various embryo biopsy strategies have been suggested, such as blastomere biopsy at the cleavage stage, trophectoderm biopsy at the blastocyst stage, polar body, and finally morula biopsy. Ensuring a careful embryo manipulation during biopsy to maintain its viability is pivotal . HoweverThe number of the embryos transferred is characterized by controversy and debate. Numerous studies support the elective single embryo transfer (eSET), especially in cases of surrogacy, as the most efficient approach to limit multiple gestation and preterm birth, which are both accompanied by adverse perinatal and neonatal outcomes , 7, 36. In contradiction to natural conceptions, pregnancies deriving from ART cycles—including surrogacy cycles—may be related to increased risk of perinatal complications. It has been indicated that the perinatal outcomes of gestational surrogacy in comparison to autologous IVF report no major increase in the risks of preterm birth, live birth rate, and congenital anomalies . In addiIn order to increase implantation rates, the method of multiple embryos transfer is opted for in some IVF cases. This practice is also adopted and perhaps even heightened in the cases of surrogacy, resulting in multiple gestations with the obstetric and perinatal complications that these may entail . IVF-surThe special conditions and the uniqueness characterizing surrogacy, the relationship, and the expectations of the commissioning couple/person towards the surrogate could complicate management. This is a situation understandably lacking control, a condition which certainly may create the basis for a pregnancy associated with an extra level of stress factors . ExposurDuring the fetal period, the surrogate mother has to abide by all agreed limitations, as she is exposed to the same pregnancy risks as any pregnant woman. This means that she is vulnerable to ectopic pregnancy or even miscarriage . ConformWithout a doubt the psychological and emotional states of the surrogate play a pivotal role in the wellbeing of the fetus. Stemming from the behavior and/or the stress level of the surrogate, her state may translate biologically to deleterious intrinsic factors that affect the wellbeing and development of the fetus. Could it be that the possible lack of acceptance of the surrogate towards recognizing the embryo and fetus as her own and the possible lack of positive outlook of the pregnancy may present a risk to the development of the fetus? It is suggested that the gestational mother may contribute to fetal development, through epigenetics, microchimerism (cells are transferred between the fetus and mother through placenta), and transport of both antibodies and nutrients . Fetal cDar's interesting study examining all issues from medical to psychosocial and legal exploring data from a large surrogacy program reported an overall mean of 37,9 weeks of gestational age at birth on surrogacy cases and specifically 38,9 weeks for singletons and 35,8 weeks for multiple births . These rWhether factors related to the surrogate pregnancy find their way towards affecting the neonatal and the period following is a subject under investigation. Many studies propose that ART offsprings—and that extends to surrogacy cases—are prone to cardiovascular diseases, presenting with higher systolic and diastolic blood pressure, obesity resulting from insulin resistance and the impaired glucose metabolism, and thyroid dysfunction with high levels of thyroid-stimulating hormone (TSH) . On the As mentioned above, the practice of multiple embryos included in the ET may result in multiple gestations often encountered in surrogacy cycles. These may result in preterm labour and delivery, in comparison to singleton , 5, 39. The solution to challenges originating from multiple gestations is for the IVF set-up to promote further the practice of elective single embryo transfer to avoid multiple gestations and the considerable risks associated with them , 36. TheNutrition of the surrogate is an important factor that could pose a risk. Insufficient nutrition during pregnancy plays an important role to the child's or even to the adult's health, as it may be responsible for the development of cardiovascular diseases, allergies, hypertension, diabetes, or either schizophrenia . This isStress levels of the surrogate during gestation could play a detrimental role. This exhaustive search did not identify studies reporting on whether maternal stress levels are higher during a surrogate pregnancy in comparison to nonsurrogate pregnancy. This fact may highlight a deficit in the literature. General population studies show a clear association between maternal stress and low birth weight or prematurity . NeonataChildren born through gestational surrogacy are legally protected, through the anonymity of the donor and surrogate's data. However, the child has the right to be informed in a specific manner on the way that he/she was born and be informed of his/her origins in general . Many stThe science of prenatal and perinatal psychology reveals that every stimulus recorded to the child's consciousness significantly determines its behavior as an adult, both physical health and mental balance. Moreover, it defines the relationships that the child forms throughout life. In addition to that, many clinical studies assume that the embryo's conscience is formed during the intrauterine period and that the perception and the feelings of the surrogate during gestation may affect infant development majorly. Medical evidence supports the fact that various neurohormones are transferred from mother to fetus during pregnancy. These are pivotal for fetal brain development, normal neural system's function, and the future child's self-confidence and intelligence . Good coIt may be that trigger points regarding the psychological status of an expectant mother are the same between surrogates and nonsurrogates. If that can be safely hypothesized, then negative factors such as prenatal maternal stress, perceptions, and feelings will be expected to equally affect both groups at the same extent. However, is it equally safe to assume that such issues and detrimental effects will burden the infants of a surrogate pregnancy further? Additional studies are required to enrich our knowledge on such important issues on surrogacy. Could it be that a surrogate pregnancy, even though it is a product of consent and informed decision of the surrogate, may differ with respect to the feelings involved regarding a natural occurring desired pregnancy?With respect to the psychological effect on the children born through surrogacy there are conflicting reports. Children born from a surrogate mother do not differ in their behavior , 3. ThesAnother study examined the impact of surrogacy—genetically linked or not—on the children's psychological wellbeing during the first three years of their life, as well as during the preschool period at the age of seven. The results assessed family processes, such as warmth, communication among members, and conflict. The study concluded that, at ages of one, two, and three, children were overall unaware of the way they were born and family relationship appeared to be warmer and more enjoyable, in comparison to family processes regarding naturally conceived children. Later, at the age of seven, children presented a more positive relationship with their mothers, in contrast to natural conception families. The study reported that family structure, for instance, male same-sex or lesbian families, seems not to influence the children's psyche, as a positive quality of family relationship was evident . In addiSurrogacy appears to be a safe approach for certain infertility cases, presenting with promising and significant results. Most studies reveal comparable data between surrogacy and IVF cycles, as surrogacy goes hand in hand with IVF techniques. During this literature review, we attempted to isolate surrogacy data and focus on the embryo during all stages from the preimplantation to the neonatal and the period thereafter, presenting the risks entailed. It became clear that the surrogate embryo and the IVF embryo present with overlap on various concepts of management, as anticipated. This study set out to delineate and highlight the similarities and differences of a surrogate cycle embryo in comparison to the standard IVF embryo, regarding the options and at times the clinical practice. Any complications arising from the IVF practice enabling surrogacy are clearly associated with a more complex management in comparison to standard IVF cases. Surrogate embryo, fetus, neonate, and infant should be identified and examined thoroughly, as the risks related to these entities may differ. Acquiring a better understanding of what dictates these differences constitutes the base for a safer practice.


Like other scientific fields, such as cosmology, high-energy physics, or even the life sciences, medicine and healthcare face the challenge of an extremely quick transformation into data-driven sciences. This challenge entails the daunting task of extracting usable knowledge from these data using algorithmic methods. In the medical context this may for instance realized through the design of medical decision support systems for diagnosis, prognosis and patient management. The intensive care unit (ICU), and by extension the whole area of critical care, is becoming one of the most data-driven clinical environments.The increasing availability of complex and heterogeneous data at the point of patient attention in critical care environments makes the development of fresh approaches to data analysis almost compulsory. Computational Intelligence (CI) and Machine Learning (ML) methods can provide such approaches and have already shown their usefulness in addressing problems in this context. The current study has a dual goal: it is first a review of the state-of-the-art on the use and application of such methods in the field of critical care. Such review is presented from the viewpoint of the different subfields of critical care, but also from the viewpoint of the different available ML and CI techniques. The second goal is presenting a collection of results that illustrate the breath of possibilities opened by ML and CI methods using a single problem, the investigation of septic shock at the ICU.We have presented a structured state-of-the-art that illustrates the broad-ranging ways in which ML and CI methods can make a difference in problems affecting the manifold areas of critical care. The potential of ML and CI has been illustrated in detail through an example concerning the sepsis pathology. The new definitions of sepsis and the relevance of using the systemic inflammatory response syndrome (SIRS) in its diagnosis have been considered. Conditional independence models have been used to address this problem, showing that SIRS depends on both organ dysfunction measured through the Sequential Organ Failure (SOFA) score and the ICU outcome, thus concluding that SIRS should still be considered in the study of the pathophysiology of Sepsis. Current assessment of the risk of dead at the ICU lacks specificity. ML and CI techniques are shown to improve the assessment using both indicators already in place and other clinical variables that are routinely measured. Kernel methods in particular are shown to provide the best performance balance while being amenable to representation through graphical models, which increases their interpretability and, with it, their likelihood to be accepted in medical practice. We are witnessing an epochal change in Biology as it quickly evolves from a wet laboratory-centered science to a data-driven endeavour , a proceData is thus quickly becoming a main concern in medicine and its availability to medical experts is a necessary step towards the development of medical decision support systems (MDSS) –6. MedicA medical environments in which data dependency comes to the fore is the critical care department (CCD) in any of its general or specialized forms: intensive care unit (ICU), surgical intensive care units (SICU), neonatal intensive care unit (NICU), or pediatric intensive care unit (PICU), This has practical implications for the use of MDSS at the point of care . As obviThe CCD conditions obviously put a strain on data acquisition and management tasks. The evaluation of clinical needs may change depending on the acuity of the patient and on the existing conditions at the point of care. The type and quantity of data captured by the bedside documentation are conditioned by changes in patient status, either through paper and electronic records, or flow sheets. It is true, though, that the medical team is ultimately responsible for the definition of what is required and, in order to support clinical decision making, it may also be necessary to include further electronic health record and monitoring devices data. These may include, amongst others, fluid intake and patient output, laboratory blood draw analyses, medical images, demographics, and so on.Medical device connectivity in the different types of ICU is in any case necessary to provide a complete clinical decision support framework. While electronic health records offer themselves unquestionable work flow benefits, documentation and charting systems are, ultimately, only as good as the data they convey. Automated and validated data collection, achieved through seamless medical device connectivity and interoperability, supported both inside and outside the hospital premises and following the patient throughout the assisting process, should augment due diligence by care providers. In other words, it should be augmented through standardized ICU data curation.Data analysis approaches that are tailored to the specific needs and limitations of the ICU environments are needed, and some very interesting approaches stem from the fields of Computational Intelligence (CI) and Machine Learning (ML), which have already demonstrated their capabilities both for MDSS design and development and as tools capable to improve hospital inpatient care .This paper has two interrelated goals. Firstly, it aims to provide a detailed up-to-date survey on the use of CI and ML for data analysis in critical care environments. Secondly, we aim to illustrate the capabilities of these methods in the critical care domain by focusing on sepsis, a major pathology that is commonplace at the ICU.ML, CI and other related methodologies for data analysis, commonly described under the umbrella term of Artificial Intelligence (AI) have, over the last decades, demonstrated real value as data analysis tools in diverse biology and health-related fields. These fields include bioinformatics , 10, genCritical care could perhaps be seen as too narrow a field to provide by itself a proper perspective on the use of ML and CI. The reality is actually very different: these types of techniques are being applied to critical care problems using approaches of remarkable depth and breadth. This situation is not new by any means: Hanson and Marshall  were alrcompartmentalization, corruption and complexity. Compartmentalization includes problems related to data privacy and anonymization, data integration from potentially heterogeneous sources, and data harmonization understood as achieving a consistent definition of concepts throughout databases. Corruption would then involve different types of data errors, including data missingness and data imprecision . Finally, complexity includes issues of state estimation, prediction, and data multi-modality, where the latter challenge draws from the stages of data pre-processing and modelling.The current paper aims to provide a state-of-the-art compact survey of ML and CI applications to problems in the area of critical care. A similar attempt by Johnson et al.  takes a The current study, instead, categorizes published studies according to several different critical care subfields, singling out in sub-sections those to which more attention has been paid, and collecting the rest in a separate sub-section.As described in the introduction, critical care patients are often technologically dependent on monitoring or life-sustaining devices. The assessment of prognosis and patient stratification making use of these combined data sources is extremely important, which highlights the importance of medical device connectivity in this patient-centric environment as an essential element of a complete clinical decision support framework.The data made available by these devices often takes the form of signal, making it the perfect target for signal processing techniques based on ML and related methods. One of the key ICU problems addressed with this approach is patient monitoring and the related design of algorithms for the implementation of patient alarms. A position editorial paper by Walsh et al.  recentlysignal acquisition, alarm generation and alarm validation. Requirements for these algorithms were also listed, including: robustness against artifacts and missing values, real-time operation capabilities, predictable behavior and methodological rigor. Imhoff et al. describe their own previous early experience with ML methods in this area [The field of alarm algorithms in critical care monitoring was considered in some detail in . There, his area , 27: a cArtificial neural networks (ANNs) were, from very early on, picked up as building blocks of the design of monitoring alarms, specifically for monitoring of patients under anesthesia , 29. A mOther somehow less standard methods applied to these area include early work using Bayesian Networks (BN)  for evenRecent work by Joshi et al.  in the dDespite the fact that we are highlighting the most popular areas of application of ML in critical care, this categorization is, to some extent, artificial because some studies cross over such categorization. An excellent example of this is the recent work by Joshi and e al.  who applThere are certain patterns to be found in the use of ML and related methods at the NICU, both from the point of view of the specific problems addressed using these methods and from the point of view of the type of methods used. Beyond the aforementioned design and development of automated alarm systems and sepsis management, the former include problems such as risk-of-death (RoD) prediction and brain development and neurology issues in neonates, amongst others.RoD or mortality prediction in the NICU has for instance been investigated for over a decade by Frize et al. In both , 43, forANNs in the latest work by Frize et al.  used in-A somehow different approach can be found in the use of ML methods for the development of MDSS for neonatal critical care assistance by Cerqueira et al. , where tML has also been used for the assessment of brain development in preterm neonates at the NICU. Recent examples of this include , 49. TheIn the area of critical care, ML and other AI-based techniques have paid much attention to the problem of sepsis pathology medical management and, very specifically, to its diagnosis and prognosis, which we discuss at length in the second part of this paper.Fuzzy systems as CI methods and rule extraction have been proposed as strategies for increasing the interpretability and usability of the results: A Fuzzy DSS for the management of post-surgical cardiac intensive care unit (CICU) patients was defined in . The proBeyond , ANNs haAnother technique often used for the prediction of sepsis is the SVM. Kim et al.  applied ML methods have achieved success in varying degrees in the problem of the prediction of mortality caused by Sepsis. In , a SeptiThe previous topic-specific sub-sections are devoted to those critical care-related problems to which, arguably, a closest attention has been paid in ML and CI. All these reviews reflect not only the manifold areas of application to critical care, but also the broad palette of methods available to practitioners in critical care.reincarnation of ANNs, very much in vogue but which is usually restricted by large data requirements) include that for the unsupervised learning of phenotypical features in longitudinal sequences of serum uric acid measurements, as investigated in [Other problems, to which perhaps less attention has been paid from this point of view include, for instance, general mortality prediction using ANN models –70 and Sgated in . The appgated in .Sepsis data analysis using ML and related methods has been the focus of the authors’ research in critical care. Therefore, the second part of this paper pays detailed attention to our work on the application of these methods to the solution of diverse problems in the management of sepsis. We use this work as an illustrative example of their capabilities and limitations as applied in the field.The official consensus definition of the sepsis pathology has substantially evolved over the last few decades. The last consensus meeting held in 2016 agreed on new definitions both for sepsis and its complications . These nUnfortunately, the calculation of the SOFA score requires to perform blood tests to assess coagulation, liver and renal function and can, as a result, be more time consuming than what the ICU environment actually affords. The quick SOFA (qSOFA) score was defined as an alternative that allows making executive decisions and admit patients into the ICU in a realistic fashion. It just assesses mental status, systolic blood pressure (SBP) and respiratory rate .Sepsis is thus defined as life-threatening organ dysfunction caused by a dysregulated host response to infection and organ dysfunction can be identified as an acute change in total SOFA score ortality .Note that these current definitions are yet to be widely adopted in day-to-day critical care. Despite this, they set the basis to validate the common ground in the study of the pathophysiology of sepsis and its prognosis at multiple levels of analysis, including the study of the inflammatory response during sepsis and its association with organ dysfunction, both from already available clinical data and at the level of transcriptomics, proteomics and metabolomics. All of this in order to achieve a better understanding the underlying mechanisms of the pathological process.A study aiming to identify key prognostic factors in patients that suffered a septic shock during their stay in the ICU is presented in this section. All analyses are based on the MEDAN database , which rThis database is publicly available and its data was analyzed using causal probabilistic networks (CPN). CPNs are accepted in computational biology and bioinformatics as capable of modeling causal relationships in a more precise fashion than standard clustering or regression models. These models also have sound statistical foundations for inferential modeling  that helCausal Explorer public library [The practical implementation of the CPNs used the  library  with theThe graph displayed in Fig. Analyzing how would SIRS relate to organ dysfunction measured through the SOFA score , to obtain new prognostic factors, understood as sets of descriptors, for the prediction of sepsis-related mortality. Importantly, the results obtained using this approach are readily interpretable for medical experts.In the experiments reported here , the proIn this work, a prospective observational cohort study of adult patients with severe sepsis was analyzed. The study was conducted at the Critical Care Department of the Vall d’Hebron University Hospital , and it was approved by the Hospital Research Ethics Committee. The database includes data from patients with severe sepsis and septic shock, both collected at the ICU by the Research Group in Shock, Organic Dysfunction and Resuscitation (SODIR), between June, 2007 and December, 2010. During this period, 354 patients with severe sepsis  were admitted in the ICU. These data consistently show the worst values during the first 24 hours of evolution for severe sepsis for all variables. Organ dysfunction was evaluated using SOFA scores, while severity was evaluated using the APACHE II score. A total of 34 features was used for the mortality prediction analyses. They are listed in full in .The FA outcome was a consistent 14-factor model. The cumulative proportion of total (standardized) sample variance explained by this model was found to be 83.27%.cardiovascular SOFA score and use of vasoactive drugs).Factor 1: Related to cardiovascular function .Factor 2: Corresponds to haematologic function .Factor 3: Corresponds to respiratory function .Factor 4: .Factor 5: Related to the micro-organism producing the sepsis and whether this sepsis is polymicrobial (24 h SSC bundles and glycaemic indices).Factor 6: .Factor 7: Corresponds to renal function .Factor 8: Related to the hepatic function .Factor 9: Corresponds to the administration of antibiotics and haemocultures taken during the first 6 h of ICU stay .Factor 10: Relates to the number of organs in dysfunction .Factor 11: Corresponds to the CNS function (Sepsis focus and base pathology).Factor 12: Related to the loci of sepsis (APACHE II score and worst lactate levels).Factor 13: .Factor 14: Weak loadings  for every given variable, these factors were mapped into different readily interpretable clinical descriptors, which can be explained as follows :function , combinefunction . It can Following the FA analysis, mortality prediction using LR was carried out using the 14-factor solution as a starting point. Performance was assessed through 10-fold cross validation. Table he model , 89 at aMechanical Ventilation and Pplateau, together with factor 13, which is related to the APACHE II score, showed the strongest effects. Factor 8 (Hepatic Function measured with the SOFA Score) and factor 10  were also found to be quite relevant. Note that the factors related to the Surviving Sepsis Campaign show no strong effect on mortality prediction using LR. This may be due to the low compliance with the Surviving Sepsis Campaign Bundles for the first 6 and 24 hours of evolution (26.18% and 44.06% respectively for the ICU under study). However, it should be pointed out that factor 9 (antibiotic administration and haemocultures) has a higher impact than factor 6 (24 h. bundles with glycaemic indexes). For the ICU under analysis, 80.22% of patients received antibiotics during the first 6 h of evolution and 77.14% had haemocultures during the same period of time. In fact, timely administration of antibiotics and performance of haemocultures are considered critical to the improvement of septic patients’ prognosis. A 10-fold cross validation yielded an Area Under the ROC Curve (AUC) of 0.78. A decision threshold of As shown in Table Comparison with LR over a selection of the original variablesExperiments continued aiming to compare the predictive ability of the FA 14-factor solution with that which could be achieved using the original data variables. For that, the most relevant clinical features were selected following a backward feature selection process (the backward feature selection removes those variables yielding non-significative Z-scores). According to this, the selected attributes were: the total number of dysfunctional organs; the APACHE II score; and the worst lactate levels. The corresponding coefficients, maximum and minimum values and Z-scores for these three variables can be found in Table LR applied to the most significant attributes a 10-fold cross validation resulted in an AUC of 0.75, which is a worse result than the one obtained from the FA solution. Following the procedure outlined in the previous subsection, a decision threshold of Comparison with the APACHE II mortality scoreA is the APACHE II score and The Risk-of-Death (ROD) formula, based on the APACHE II score, is defined as :1\documeAll these previously reviewed studies investigated the dependence relations between the observed variables and clinical traits and exploited their marginalization to study sepsis and its prognosis through CIM, FA, LR and the APACHE II score. In this section, the use of kernel methods to analyse the same data is explored.In , data weIn this case, the data for analysis come from the MIMIC II –93 publiThe current data availability surplus in medicine in general and critical care in particular poses increasingly complex challenges. ML and related data analysis approaches have provided, over time, a substantial corpus of evidence to support their value in the role usable knowledge extraction from medical data. In this paper, we have surveyed in some detail not only this value, but also the main challenges they face.The potential of ML in the area has been exemplified by focusing on the sepsis pathology in particular. The new definitions of sepsis and the relevance of using SIRS in its diagnosis have, of late, being a matter of hot debate in the critical care research community. To shed some light on this debate, we have used conditional independence models to analyze sepsis data, showing evidence of a dependence of SIRS on both organ dysfunction measured through the SOFA score and on the ICU outcome. In the light of these results, it is our opinion that the SIRS should still be considered in the study of the pathophysiology of sepsis.One of the main limitations of the current ICU application of quantitative methods to the assessment of ROD is their lack of specificity , which not only puts an extra risk on an already severely affected patient population, but also results in an unnecessary burden for National Health Systems. In this regard, ML and related techniques can play an important role by improving overall performance through a combination of the indicators already in use with further clinical variables, all of which are routinely measured at the point of care. In this paper, we have attempted to show how a representation over latent factors, extracted from the originally mesured features, may be useful. Other possible approaches, very well suited to medical protocols due to their interpretability and explanatory power, are those based on Classification and Regression Trees, as shown in the state-of-the art. Along this lines, it may be also interesting to use Gradient Boosting Trees or Random Forest models for parameter selection and prognosis assessment in future research.Attending to the nature of clinical data available in the ICU, it might be possible to better assess prognosis through a proper embedding of the data. The techniques presented in the case study reported in this paper are related to regular exponential families in general and to the multinomial and Gaussian exponential families that resulted in the generative kernels outlined in previous sections. The accuracy of routinely used methods for assessing prognosis of septic patients in the ICU (LR and the APACHE II) yield acceptable accuracy, but their performance in terms of specificity is still limited. The RVM and LR models applied over latent factors have been shown to yield an acceptable performance. However, the kernel methods have shown to provide the best balance in all these performance parameters. It is also worth mentioning that the QBK and the simplified Fisher kernel yielded the best results, as reported in Table In conclusion, we believe that data ML methods have proven to be valuable in an extremely data-intensive environment such as the ICU. They can provide actionable and interpretable prognostic indicators for sepsis and also insight on the relevance of different clinical traits that are not recommended to be used in the current protocols such as the SIRS. In this regard, we believe that future work in the use of ML for the study the role of omics data  during the inflammatory cascade during sepsis may further improve our understanding of the mechanisms and physiopathology of sepsis.


Entrepreneurial followers are defined as the crucial members of a specific entrepreneurial team and do not include the leader or normal employees in the present paper. This population can be viewed as indispensable factors in the success of entrepreneurship, especially in the start-up stage. In addition, according to the following time, they can be divided into two groups, namely long-term entrepreneurial followers and short-term entrepreneurial followers. However, studies focusing on entrepreneurship cultivation for entrepreneurial followers are relatively few. The main purpose of this paper is to determine the needs of Chinese entrepreneurial followers in entrepreneurship cultivation from the early stage of entrepreneurship. In this paper, a sample of 200 long-term entrepreneurial followers from Tianfu New Area in China was investigated. To enable the researchers to explore the unique opinions of entrepreneurial followers, a mixed data collection approach that combined interviews and questionnaires was chosen in this study. The results revealed following findings: (a) high levels of social capital, good entrepreneurial opportunities and projects, and highly cooperative teams were viewed as the most important factors for entrepreneurship by entrepreneurial followers in China; (b) most entrepreneurial followers believed that the primary difficulty in the cultivation process was the inefficiency in talent training mechanism; and (c) nearly 40% of samples suggested that the cultivation and enhancement of local talents should be firstly carried out by the Chinese government, indicating a gap between the supporting force for local and returned talents in China. In addition, various types of incentive policies and good environments for talent growth were also considered as important suggestions by entrepreneurial followers. We found that unlike entrepreneurial leaders, entrepreneurial followers focus more on income expectation, and personal development rather than supporting the development of companies in China. These findings should be viewed as priorities when enhancing current entrepreneurship cultivation in China. Entrepreneurship has attracted the attention of policymakers, economists, and scholars around the world. In general, entrepreneurship can be defined as an employment opportunity enabling individuals to be self-employed . During Moreover, existing studies also suggested that, despite the important role played by the entrepreneurial leader as a lone hero, their followers also hold influence in promoting the development of entrepreneurship, especially in the early stages . HoweverThus, in order to fill this theoretical gap that currently exists in the literature, the present paper aims to propose the definition of entrepreneurial followers. We argued that entrepreneurial followers could be defined as the crucial members  of a specific entrepreneurial team and do not include the leader or normal employees. They have highly consistent interests or beliefs with leaders and are generally responsible for different important components of entrepreneurial activities. Instead of being simply viewed as the people being led, entrepreneurial followers are precious human resources for entrepreneurship with characteristics of initiative, activeness, enthusiasm, and creativity.In addition, only a little evidence has been proposed to support the view that there are considerable differences in personal characteristics and expectations between entrepreneurial leaders and followers. As an example, The present paper is organized as follows. The next section provides a literature review about the topic. The section “Materials and Methods” demonstrates the applied method of this paper. The section “Results” presents the empirical results. The section “Conclusion and Discussion” draw on the main conclusion and implications extracted from the results.Previous studies indicated that the entrepreneurship is important for social, national, and industrial development . For insMuch evidence to support that entrepreneurship capabilities can be cultivated and are not fixed personal features has been published in existing research. For instance, From a framework perspective, In addition to the temporal perspective, many scholars have researched entrepreneurship cultivation from a spatial point of view, in which the United States  and the In the view of entrepreneurial followers, some scholars have implemented empirical studies that focus on various related issues . For insMoreover, according to the following time, we argued that the entrepreneurial followers can be divided into two categories: long-term entrepreneurial followers and short-term entrepreneurial followers. In comparison, the former shows greater loyalty and autonomy, and has more interest or belief foundation with the leaders. In addition, the behaviors of leader are also more likely to be shaped and altered by the former because the long-term closely personal, social and working relationships between them. Many historical examples have proved the importance of long-term entrepreneurial followers for the success of entrepreneurship. As Since the goal of this study is to both “explore” and “measure” the needs of entrepreneurial followers in entrepreneurship cultivation, it not only demands a more qualitative design , but alsjiaozi (a kind of Chinese ancient currency) was also firstly invented in Chengdu during the time of the Northern Song Dynasty, which created the paper currency system that is still in use today. In addition, the receptive and inclusive culture that is rooted in Sichuan province is currently a fundamental characteristic of the Tianfu New Area. Based on recent developments, officials have planned for the construction of the Luxi Chile Valley Technology Innovation and High-Tech Service Function Area in the Tianfu New Area, and the construction of several new parks, such as the Tianfu Haichuang Park and the Tianfu Science and Technology Park, has already begun. Additionally, it has seen the introduction of key national laboratories such as the Industrial Big Data National Engineering Laboratory, which has welcomed many renowned scientific-research universities and institutions, including but not limited to Tsinghua University, Peking University, Beihang University, and the Chengdu Science Research Center of Chinese Academy of Sciences. Moreover, the Tianfu New Area is the location of many well-known enterprises such as the Chengdu Mengsheng Electronics Limited Company and the China Aerospace Science and Industry Corporation. In recent years, several intellectual property service agencies (represented by Liushen Law Firm) and science and technology financial service agencies  have successfully settled in the area.Our data source is the Tianfu New Area, Chengdu city, Sichuan province, China. Since ancient times, Chengdu was an important center where entrepreneurs gathered. For example, Bing Li, who was a world-famous hydraulic engineer in the Warring States Period, designed the Dujiangyan Irrigation System. The The reason for choosing this area as our data source is because it is 1 of 19 state-level “new” areas in China that was established upon approval of the State Council in October 2014. In 2017, the Tianfu New Area introduced the “Policy Proposals for Accelerating Technological Innovation and Developing High-Tech Services” and the “Implementing Measures for the “Tianfu Elite Program” of the Chengdu Zone of Tianfu New Area.” A special fund has also been established, with 1 billion RMB allocated for talent development. Since its launch in 2014, the Tianfu New Area has attracted more than 1,400 innovative enterprises and 14,600 entrepreneurs, including 12 national experts, 21 provincial experts, 2 expert teams, 24 experts chosen by the Chengdu Talent Planning Program, and 9 foreign experts. In addition, entrepreneurship has developed in these areas in a considerably active way. In addition, there is a large number of entrepreneurial teams at different stages of the entrepreneurship process, thus providing a dedicated support for our investigation. We applied the typical probability sampling method to include companies across various industries in this area. The industries included but were not limited to the technology service industry, the information service industry, the business service industry, the cultural and creative industry, and the high-tech manufacturing industry.Companies from all seven districts  were considered to ensure that the participants included in this study allowed for optimal generalization. By following this rule, based on the typical probability sampling method, 10 companies were selected. According to the sample, the following six points can be noticed: (a) The registered place of all surveyed companies is in Sichuan province; (b) 73.3% of selected companies are in the creation or seed stages; (c) the registration time of 63.3% of companies is 2015, and the others were registered in 2014; (d) the registered capital of 30% of surveyed companies is below 500,000 RMB, 56.7% is between 1 million RMB (including) and 5 million RMB, and 13.3% is more than 10 million RMB; (e) the number of followers in 53.4% of companies is under 10, and it is between 12 and 45 in 40% of the companies; and (f) the asset value of 40% companies is below 1 million RMB, and 26.7% of companies have an asset value of between 1 and 5 million RMB.As previously mentioned, entrepreneurial followers refer to the crucial members of an entrepreneurial team, aside from the leader and normal employees. In addition, because the long-term entrepreneurial followers generally play a more important role for the development of companies compared to short-terms ones, they have greater significance to be researched, to a large extent. Thus, in the present paper, only the first-generation entrepreneurial followers of these 10 companies who have followed the leaders for a long period of time  and made significant contributions to the selected companies were considered.By following By applying this mixed data collection method, we surveyed and interviewed all of the long-term entrepreneurial followers separately and considered 2 rules for implementing the filtration process of surveys: (a) Ensuring the completeness and validity of the surveys; (b) ensuring industry diversity of the investigated companies. After the data-cleaning procedure, we obtained 200 samples. All of the data obtained from the participants were encrypted to ensure data security.Within the process of qualitative data analysis, two researchers (XD and YL) of this paper transformed pronouns and other indexical terms into nominal meanings in order to provide clearer surrounding concepts. Further, these concepts or comments were integrated and categorized based on their central themes by all the researchers of this paper.The collected quantitative data were analyzed using Stata version 14.0. Firstly, the crossover analyses between the entrepreneurship industry and education levels, and between the number of entrepreneurial followers and the annual revenues of the researched companies were carried out. Subsequently, differences in samples’ responses on each question contained in the survey were compared descriptively based on the calculated percentages. The analysis was conducted by XD and YL with review by CT and DT.P value of Bartlett’s sphericity test is less than 0.05. Thus, the validity of the survey can be guaranteed.The reliability test cannot be carried out in our study because the designed survey does not contain scales. In this view, The investigated personal characteristics of the entrepreneurial followers include three aspects—namely, age, education level, and the entrepreneurship industry they work in. The descriptive graphs are shown in According to In addition, some indirectly evidence proving the contribution of entrepreneurial followers on the development of entrepreneurial companies has been provide by some existing papers . In ordeIn the interview, 11 potential factors that influence entrepreneurship were considered, and we asked the entrepreneurial followers to choose the most important ones. The responding results are shown in It can be seen from guanxi  network, especially for start-up ventures  network in entrepreneurship activities, which is a unique phenomenon in China.In order to realize this purpose, three main areas were studied in this paper—namely, influencing factors for entrepreneurship, difficulties faced by entrepreneurial followers at the start-up stage, and suggestions for the improvement of entrepreneurship cultivation systems at the start-up stage. The results show that high levels of social capital, good entrepreneurial opportunities and projects, and highly cooperative teams were viewed as vital foundations of entrepreneurship by samples. This finding indicates that Chinese entrepreneurial followers pay more attention to income expectation and personal development rather than supports that contribute to the development of companies. In addition, they are also concerned about the Moreover, nearly half of the studied entrepreneurial followers held that the difficulty in transforming research results was the most serious problem in entrepreneurship in China, and more than a fifth of those believed that low salaries present considerable difficulties as well. With respect to the difficulties faced by Chinese entrepreneurial followers in the cultivation process, talent training mechanism was considered as the primary one. It seems that rather than income expectation, Chinese entrepreneurial followers place more importance on their personal development; in most cases, higher capability often equates to higher income. Furthermore, as nearly 40% of entrepreneurial followers suggested that the Chinese government should pay more attention to the cultivation of local talents, an unbalance and unfair distribution of supports between local and returned talents seems to be proved. Additionally, we also found that the lack of incentive mechanism is also an existing problem. These points reflect some dominant problems of the current entrepreneurship cultivation system in China.Our analysis makes some important contributions to current knowledge. First, given the importance of entrepreneurial followers for the success of entrepreneurship , our resSecond, unlike existing research, which only focused on entrepreneurship cultivation for entrepreneurial leaders or entrepreneurs as a whole , the preThird, through multiple investigation angles and various experimental methods, we tested the needs of entrepreneurial followers in entrepreneurship cultivation from the start-up stage. Our findings focused on the factors that influence entrepreneurship, the current difficulties faced by followers, and improvement suggestions for entrepreneurial cultivation, thus making our conclusion more credible and forming a reasonable, logical relationship to enable related researchers to comprehensively understand this point. Thus, this study contributes to the literature of entrepreneurship cultivation and entrepreneurial followers.The present paper has some practical implications, as it can help policymakers, institutional investors, entrepreneurial leaders design and carry out related measures to improve the current entrepreneurship cultivation system in China and abroad. First, material incentives for the basic conditions of entrepreneurial followers should be established in order to provide them with better living and service environments. Second, the time and space advantages for cooperation between industry and university research as well as fair investment and financing systems should be built though institutional incentives. This would strengthen the technological beliefs and innovative pursuits of entrepreneurial followers. Third, traditional culture should be pertinently integrated into the entrepreneurship education system in order to enhance entrepreneurship awareness and the capacity of entrepreneurial followers.However, there are still some limitations to the present paper:I.This study only focused on the entrepreneurial followers in the Tianfu New Area, which limited the generality of our findings. Future studies should consider a larger sample size of multiple organizations and countries. This will make the results more representative and specific.II.This paper only studied entrepreneurial companies at the start-up stage due to their relatively significant representativeness. However, the cultivation process is also extremely important for entrepreneurial companies in various other stages. Thus, for a more comprehensive perspective, future studies should pay attention to entrepreneurial enterprises at different growth stages.The main purpose of this paper was to answer the question that what do entrepreneurial followers really need in entrepreneurship cultivation at the start-up stage. Based on the results, following conclusions could be gained. First, high levels of social capital, good entrepreneurial opportunities and projects, and highly cooperative teams were viewed as the most important factors for entrepreneurship by entrepreneurial followers in China. Second, entrepreneurial followers considered the difficulty in transforming research results, shortage in talent training mechanism, and low salaries as main difficulties in the entrepreneurship cultivation at the start-up stage. Third, most samples believed that the government should first cultivate and enhance local talents.These findings indicate that entrepreneurial followers in China pay more attention to their personal development than income expectation, and the social relationship in entrepreneurship activities is also an important concern. In addition, it should be noted that there is a gap between the supporting force of the government for local versus returned talents, and a lack of incentive mechanism in China.Therefore, we claimed that the Chinese government should delivery more rational policies focusing on the cultivation of entrepreneurial followers, especially for local ones. Moreover, various types of incentive policies and good environments for talent growth were also considered as the aspects to be improved in future policies.This study was carried out in accordance with the recommendations of ethic guidelines, Ethic Committee of Beijing Jiaotong University with written informed consent from all subjects. All subjects gave written informed consent in accordance with the Declaration of Helsinki. The protocol was approved by the Ethic Committee of Beijing Jiaotong University.XD, CT, and DT provided substantial contributions to the research conception and design. XD and YL analyzed and interpreted the data. XD, CT, and DT wrote the manuscript and provided critical revisions of the manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Tendinopathies are very common in general population and a huge number of tendon-related procedures take place annually worldwide, with significant socio-economic repercussions. Numerous treatment options are commonly used for tendon disorders. Besides pharmacological and physical therapy, nutrition could represent an additional tool for preventing and treating this complex pathology that deserve a multidisciplinary approach. In recent years, nutraceutical products are growing up in popularity since these seem to favor the prevention and the healing processes of tendon injuries. This narrative literature review aims to summarize current understanding and the areas of ongoing research about the management of tendinopathies with the help of oral supplementation. Tendon disorders are a class of pathology that includes traumatic injuries as well as chronic diseases, such as tendinopathy. They represent some of the most frequent orthopedic diagnosis, accounting for over 30% of all musculoskeletal consultations . Over 30Tendon disorders are very common in sports. Physical activity determines much stress and force on the tendinous part of the muscle-tendon unit, increasing the risk of tendon injury. Around 50% of sport-related injuries are due to overuse conditions and the majority of these involves tendons . The rotThe tendons are “mechanical bridges”. They are strong fibrous structures of pearly color that connect the muscles to the bones and have the main function of transforming the force generated by muscle contraction into movement. In addition to this, they are able to absorb external forces in order to limit muscle overloads and act as temporary energy storage devices. Thanks to their proprioceptive properties, the tendons are also of primary importance in postural adjustments. Anatomically they are organized according to a hierarchical scheme. The smallest building blocks of tendon are collagen molecules. These combine to form tropocollagen helixes. A group of five tropocollagen molecules are bound together by intermolecular crosslinks to form a microfibril  and more microfibrils, forming together the fibrils, which have diameters ranging from approximately 10 to 500 nm. The latter grouping together will form collagen fibers with the fibers aggregating once again to make up the largest subunit of tendon, the fascicle. Fascicles are visible to the naked eye, with diameters ranging from 150 to 500 μm. A very thin lamina of connective tissue, endotenon, binds the fascicles to make the complete tendon unit. The tendon surface is covered by the epitenon, which is a connective tissue sheath continuous with the endotenon. It facilitates the sliding of the various structural units and holds blood and lymphatic vessels and nerve structures. Finally, in regions far from joints, an additional loose connective tissue layer, the paratenon, surrounds the tendons and facilitates movement of tendons below the skin .Structurally, the tendons consist of a cellular part, and an extracellular matrix. The tenoblasts are immature spindle-shaped cells. With maturation, they take on a more elongated shape and become tenocytes . These tThe tendon cells are surrounded and supported by the extracellular matrix. The ECM is a complex structure made up of three major classes of biomolecules: structural proteins (collagen and elastin), specialized proteins , and proteoglycans . Tendon The main component of the ECM is type I collagen, which accounts for 70–80% of the dry weight of the tendon and represents almost 95% of the total collagen. Other collagens including collagen types II, III, IV, V, VI, IX, X, XII, and XIV have also been found in small quantities within tendon. Elastic fibers (2% of dry weight) give the extensibility, allowing the tendon to stretch in the necessary directions. Proteoglycans are protein–polysaccharide complexes (GAGs) that have the ability to retain water and are responsible for the resistance of the tendons to compressive forces ,23. In aThe term “tendinopathy” describes a clinical condition characterized by pain, swelling, and functional limitation of the tendon and contiguous anatomical structures. Except for the infrequent tendon ruptures of a traumatic or iatrogenic nature , most tendon pathologies are due to overuse conditions both in the working environment and in sport. Histologically in the typical conditions of overuse, around and inside the tendon, it is rarer to find inflammatory processes. Therefore, the term “tendinitis” is not adapted to describe this condition. It has been shown that there is no inflammatory process at the base of the tendinopathies, if not in the very early stages of the disease (first three weeks from the onset). In fact, in most cases, degenerative phenomena are detected rather than inflammatory, and the use of corticosteroids or anti-inflammatory drugs is mostly ineffective . RegularAlthough it is possible to find inflammatory cells, the most represented histological aspect is the degenerative one. Microscopically the collagen fibers lose their parallel arrangement, appear disorganized and there is increased extracellular matrix .At the level of the extracellular matrix, it is frequently observable mucoid material with a simultaneous separation of the collagen fibers. Degenerate fibers can be replaced by calcification or lipid infiltrates that give rise to the well-known phenomenon of tendolipomatosis. Therefore, there is a marked increase of type III collagen which, compared to type I collagen, is characterized by a lower number of cross-links between and within the tropocollagen units. The clinical relevance of the various degenerative aspects  remains uncertain: either alone or in combination, they are also found in a high percentage of healthy and asymptomatic individuals over the age of 35 . In addiNumerous treatment options are proposed in the treatment of patients affected by tendinopathies. Usually, they can be grouped in pharmacological therapies, physical therapies, and therapeutic exercise.Pharmacological treatment of tendinopathies is difficult. Anatomically, these structures suffer from a reduced vascularization and therefore drug availability in the target tissue is low. Moreover, while the effectiveness of drugs on other components of the musculoskeletal system has been proved, such as bisphosphonates in bone , myorelaFor these reasons, painkillers administrated orally and/or parenterally are often used in the treatment of tendinopathies. NSAIDs , SAIDs , and other alternative injective approaches have been used.NSAIDs, in the absence of a manifest inflammatory process, do not change the course of chronic tendinopathy  and can Other therapeutic options exist (like trinitrine glycerine patches) but are less used and not available in several countries: among them, only a few have been tested in clinic  has become popular in recent years for the treatment of soft tissue disorders, including calcific tendinopathies of the rotator cuff, epicondylitis, plantar fasciitis, Achilles and patellar tendinopathy. It seems they promote the differentiation of tendon derived stem cells (TDSCs), the proliferation of tenocytes and the synthesis of collagen. Moreover, they reduce the production of interleukins and metalloproteases in damaged tendons  and deteIrrefutably, a cornerstone in the treatment of tendinopathy is represented by therapeutic exercise. Several protocols of exercise have been proposed and investigated. Although the exact mechanism is not still completely understood, eccentric exercise with lengthening of muscle during contraction has had a major role in the treatment of tendinopathy. Indeed, it seems to be very effective, especially in the management of patients affected by tendinopathies of the Achilles and patellar tendon. These exercises have been shown to promote cross-linking of collagen fibers and facilitate tendon remodeling  and causNo single protocols have shown a definite superiority versus other protocols and the adoption of several protocols of exercise, including eccentric exercise, seems to guide the rehabilitation process, as load is able to stimulate tissue regeneration and reorganization. Doubts about volume, frequencies, velocity, and pain perception during exercise still remain .Many other types of treatment for tendinopathies have been described in the literature but no single therapy has been shown to be more effective than others and often the same technique has shown ambiguous results. The common denominator of the different approaches proposed in the literature is to promote a regenerative response of the tendinous tissue. In fact, due to new initiatives in the pathophysiology of tendon injuries, the use of therapies with anti-inflammatory effect should be abandoned in favor of strategies that promote tissue regeneration.In addition to pharmacological and physical therapy, nutrition could represent an effective tool for preventing and treating a pathology that requires, due to its complexity, a multidisciplinary approach. The use of nutritional supplements should be carefully taken into consideration, due to their metabolic effects; for example, the abuse of anabolic-androgenic steroids shows an increased risk of upper body tendon rupture . ParticuSome metabolic pathological diet-related conditions could affect tendon function. For example, hypercholesterolemia is a known risk factor for the development of tendinopathy and is a clinical finding frequently seen in cases of rotator cuff tear and Achilles tendon rupture. Furthermore, the management of hypercholesterolemia through statin therapy has shown positive effects on tendon healing . DiabeteDiet plays a primary role in the homeostasis of all tissues and it is an important component in the etiology and management of various medical conditions that can contribute to the development of tendon pathology. The role of dietary supplementation on tissue function and architecture is not a recent topic of research; indeed, in past years, several studies ,65 have In general, nutrients can be classified into three categories: macronutrients, micronutrients, and water.Water is essential for life and it represents a critical nutrient whose absence would be quickly lethal ; its impThe former consists of carbohydrates, lipids, and proteins. Carbohydrates are the main source of energy that is mainly used for muscle and nervous system metabolism. Proteins are essential for anabolic and repair processes in the musculoskeletal and other tissues and in hormone synthesis. Lipids are an energy source of storage. Vitamins and minerals are considered micronutrients and are required in smaller quantities. Vitamins act as enzymatic catalysts and regulate the chemical reactions that take place in metabolic processes. Minerals have a structural and metabolic function. For example, the matrix metal proteases (MMPs) are zinc-dependent enzymes that play a key role in the metabolism of tendon tissue. Many of the micronutrients are essential and as such must be integrated through the diet .Vitamin C deficiency is not common in the general population of developed countries but can occur in undernourished and/or digestive problems . It can lead to scurvy, hemarthrosis, synovitis, and arthralgia. Ascorbic acid is well known for its antioxidant properties and as a cofactor in two critical stages of collagen synthesis: hydroxylation of proline and lysine to hydroxyproline and hydroxylysine . This inVitamin D, in addition to regulating bone metabolism, also acts directly on the synthesis of collagen by the tenocytes. The addition of vitamin D in fibroblast culture media obtained from human tendons demonstrated a dose-dependent anabolic effect with progressive increase in type I collagen mRNA levels and at the same time a reduction in the reactive species of oxygen and expression of the metal protease of the matrix (MMPs). These data demonstrate a positive effect of this vitamin on tendon tissue, and its deficiency could be a limiting factor for collagen synthesis and cause increased exposure to oxidative stress . In anotAmino acids are the fundamental units for protein synthesis. Among them a positive relationship between leucine and collagen synthesis has been demonstrated. It is an essential element that is required to be introduced with the diet. Several studies have shown this relationship. In one of these, malnourished mice were subjected to a normal diet (control) and enriched with leucine (intervention). Both groups were further divided according to the level of physical activity to which they were subjected. The main result was the demonstration of a positive effect of the high leucine content diet on collagen synthesis especially in the subgroup subjected to physical exercise. Leucine has led to an increase in hydroxyproline levels which, besides being a fundamental component of collagen, plays an essential role in fiber stability . GlycineAn uncontrolled diet rich in saturated fatty acids can lead to hypercholesterolemia which, as is known, correlates negatively with tissue homeostasis even at tendon level. The higher proportion of cholesterol is carried within the low density lipoprotein (LDL). The oxidized form (oxLDL) has a high pathogenetic potential. A previous research  have shoSome of the most common supplements proposed to preserve and improve the function of connective tissue, are represented by glucosamine and chondroitin sulfate. Several in vivo and in vitro studies ,83 have Curcumin is a powerful antioxidant extracted from curcuma longa that shows interesting characteristics. In addition to its antioxidant potential, it has shown positive effects on cell regeneration, wound healing and negative effects on neo-angiogenesis . In addition, inhibition activity was observed with respect to the matrix metal proteases (MMPs) . In an iSince the 1960s, several studies ,89 have There are two other substances that often appear in nutraceutical preparations, boswelic acid and methylsulfonylmethane, of which an anti-inflammatory activity has been demonstrated and with positive effects on pain in muscle and tendon disorders ,91,92. IIn conclusion, the effectiveness of oral supplements in the management of tendinopathies have been widely investigated by numerous clinical studies; results tend to confirm preclinical evaluations, but are biased as multiple substances were included in the same formulation and poor methodology was adopted ,92. For There are many pathways through which nutrition can positively or negatively affect tendon homeostasis. In recent years, nutraceutical products are multiplying that seem to favor the healing processes of tendon injuries and are likely to play a role as prevention tools. The preclinical results seem encouraging even if the same aspect in literature is still too limited. Indeed, the management of tendinopathies with the aid of oral supplementation is a relatively new approach. A specific evaluation of each substance is difficult, also because most of the time combinations of these elements are used and “multivitamins” combinations are adopted in athletic and general population .Their application could have a role in tendinopathy’s prevention, in the therapeutic management of acute and chronic tendinopathy, and in the rehabilitation phase, during with some results showed improvement in the rehabilitation process .Moreover, nutraceutical supplementation could be used in combination with other therapeutic approach, such as shock wave treatment, with positive effects on pain and function .However, further researches are needed to better understand how these substances interact with cell and tissue biology in order to consciously manage nutraceutics as a therapeutic options for tendinopathies, in which a multidisciplinary approach is mandatory.


Desulfovibrio vulgaris in a closed system. Previous attempts to model SRB have resulted in complex or highly specific models that are not easily adapted to the study of SRB in different environments, such as the gastrointestinal tract. We propose a simpler, Monod-based model that allows for easy alteration of both key parameter values and the governing equations to enable model adaptation. To prevent any incorrect assumptions about the nature of SRB metabolic pathways, we structure the model to consider only the concentrations of initial and final metabolites in a pathway, which circumvents the current uncertainty around hydrogen cycling by SRB. We parameterise our model using experiments with varied initial substrate conditions, obtaining parameter values that compare well with experimental estimates in the literature. We then validate our model against four independent experiments involving D. vulgaris with further variations to substrate availability. Further use of the model will be possible in a number of settings, notably as part of larger models studying the metabolic interactions between SRB and other hydrogenotrophic microbes in the human gastrointestinal tract and how this relates to functional disorders.Sulphate-reducing bacteria (SRB) are studied across a range of scientific fields due to their characteristic ability to metabolise sulphate and produce hydrogen sulphide, which can lead to significant consequences for human activities. Importantly, they are members of the human gastrointestinal microbial population, contributing to the metabolism of dietary and host secreted molecules found in this environment. The role of the microbiota in host digestion is well studied, but the full role of SRB in this process has not been established. Moreover, from a human health perspective, SRB have been implicated in a number of functional gastrointestinal disorders such as Irritable Bowel Syndrome and the development of colorectal cancer. To assist with the study of SRB, we present a mathematical model for the growth and metabolism of the well-studied SRB,  The funorrosion , and in orrosion . Less clf faeces , but varf faeces  and betwf faeces . These boduction  and the oduction . The impAnother key molecule in SRB metabolism is elemental hydrogen. Alongside methanogens and reductive acetogens, SRB can metabolise free hydrogen present in the GIT, utilising it in the reduction of sulphate . The sulDesulfovibrio vulgaris, grown on substrates found in the GIT , as these metabolites represent important initial and final metabolites in the major metabolic pathways of D. vulgaris  produced in the oxidation of lactate and the water molecules produced in the reduction of sulphate are not included in the model, as they play no further role in the metabolism of D. vulgaris. Moreover, we assume that the culture remains well buffered throughout the experiment, therefore pH is not altered by changing concentrations of bicarbonate or other metabolites. There have been reports of bicarbonate as a growth-limiting molecule for other bacterial strains . These units were chosen to align with data sources for both the calibration and validation of the model. The model is based on Monod kinetics for bacterial growth in a batch culture environment . Monod kL; mM) byFollowing Monod kinetics, we model the rate of change in lactate concentration  and YL denotes the biomass yield (mg L–1 mM–1) of D. vulgaris when grown on lactate. KL is the Monod constant (mM) for this bacterium and substrate, also referred to as the half-saturation constant. This value is the concentration of substrate required for the bacterium to attain half of its maximum growth rate. X is the concentration of bacterial cells in the medium (mg L–1).where μD. vulgaris, although the mechanism is not clear (Haq (mM), increases. Equation 1 then becomesIt is known that high concentrations of hydrogen in the medium inhibit the metabolism of lactate by certain SRB, including ot clear . As suchHmax (mM) is the aqueous hydrogen concentration above which lactate degradation is completely inhibited. This formulation also ensures that the rate of lactate degradation reduces proportionally to the aqueous hydrogen concentration. To ensure that the model is robust to hydrogen concentrations above Hmax, we add the following condition:where S; mM) is given byThe sulphate concentration  and YS is the biomass yield (mg L–1 mM–1) of D. vulgaris during sulphate reduction. KS and KH denote the Monod constants (mM) for sulphate and hydrogen, respectively.Sulphate and hydrogen are both required for the formation of HWe assume that the aqueous hydrogen concentration is influenced by hydrogen production during the oxidation of lactate, hydrogen consumption in the reduction of sulphate, and liquid-gas transfer of hydrogen. The rate of change in the concentration of aqueous hydrogen isbLH is the stoichiometric constant for moles of hydrogen produced per mole lactate metabolised and bHP is the stoichiometric constant for moles of hydrogen required to reduce one mole of sulphate. Hg is the gaseous hydrogen concentration, measured in atmospheres, and mass transfer between the aqueous and gaseous phases is assumed to be linear, withwhere kL  and the surface area, a, across which mass transfer may occur. Although other, more complex models do exist for mass transfer between two phases, as only the gaseous hydrogen concentration data is available here, we are limited in our ability to parameterise a more complex model. Although the simplicity of this representation may result in sub-optimal representation of the hydrogen dynamics, we also seek to minimise the number of fitted parameter values in our model, and thus the film model described here is sufficient for our purposes. kLa has the unit h–1 and Vg and Vaq (mL) are the fixed volumes of the gaseous and aqueous phases, respectively. ρH (atm mM–1) is the Henry conversion constant for hydrogen. Hg is measured in atmospheres, whereas Haq is given in mM concentration, therefore we adapt the gas transfer equation used in H value of 1.364 atm mM–1.Equation 5 represents a simple mass transfer model as explained in A) and H2S (P) concentrations are proportional to the rates of change in the concentrations of lactate and sulphate, respectively.The rates of change in acetate , is proportional to the change in lactate and sulphate concentrations, with consideration of the biomass yield terms (assuming the energy requirements for cell maintenance are negligible relative to the growth requirements).Finally, the concentration of bacterial cells in the medium, D. vulgaris under our set of assumptions. A summary of model notation is given in The system consisting of Eq. 2–8 fully describes the metabolism of 1). The mathematical model of Time-course data was captured from the literature using image capturing and graphical input software in MATLAB  technique was implemented over 200,000 MCMC iterations. A non-parametric distribution was then fitted to the MCMC sample for each of the nine parameters estimated. The cumulative density function of this distribution was used to obtain a 95% confidence interval.To compare the proposed model with the existing model of n is the number of data points (63), K is the number of parameters of the model and log(ℒ(θ)) is the log likelihood function for the model. Following where wi, for each model as follows  resulting in 50% growth inhibition , compared to seven fitted and three experimentally estimated parameters  in Regarding dynamics in the GIT, current existing data from rodent models support the increased efficiency of carbohydrate breakdown by saccharolytic bacteria in the presence of either a methanogen or acetogen due to hydrogen metabolism by these microbes . HoweverIt is our intention to use the SRB model presented here as part of a larger model including other hydrogenotrophic and hydrogenogenic microbes of the human GIT, to examine the role of hydrogen in this environment. Mathematical models for the GIT microbiota are available , 2017, bThe data supporting the conclusions of this manuscript will be made available by the authors, without undue reservation, to any qualified researcher.NS performed the mathematical modelling and drafted the manuscript. All authors contributed to model and manuscript revision, and read and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.