To document the experience of three groups of Family Planning service providers participating in task-shifting for the provision of subcutaneous depot-medroxyprogesterone acetate (DMPA-SC) at the community level in the DRC.This article compares results from interviews with DMPA-SC providers in two separate pilot studies: 1) 53 medical and nursing school students teaching women how to self-inject (2016–2017); and 2) 34 lay community health workers providing DMPA-SC in rural areas of Lualaba (2017). All providers gave information on socio-demographic characteristics, recruitment,) training, supervision, experience and satisfaction with the provision of DMPA-SC. The paper examines variations in responses from the different provider cadres.Despite substantive variations in provider profiles in terms of age, educational and marital status, reported levels of satisfaction with offering DMPA-SC in the community were consistently high. Over 90% of all providers declared being comfortable or very comfortable interacting with FP clients, and more than three quarters of them were very comfortable performing an injection. Over 90% of Lualaba providers and over 80% of student providers gave correct responses to DMPA-SC protocol questions regarding referral of clients to facilities and side-effects management. The vast majority declared being (very) satisfied with their experience providing DMPA-SC.Providers with and without a clinical background, when properly trained and supervised, can provide DMPA-SC at the community level in both urban and rural settings of the DRC. Support strategies from the Family Planning environment  are key to engaging community health workers and sustainably leveraging task-shifting opportunities.This study provides additional evidence on the acceptability and feasibility of task-shifting in relation to DMCP-SC and supports further scale-up efforts. The first pilot used 53 students to teach women in target neighborhoods to self-inject the contraceptive. The providers were recruited by faculty in large, government-accredited medical and nursing schools among students who had completed clinical modules on injection, volunteered to participate and successfully completed a 6 days training on providing the full range of contraceptives authorized for community-based provision , referring women to facilities for additional FP services and training interested clients to self-inject DMPA-SC. The schools, supported by the project partners, provided the students with vests, hats, contraceptives (including 15 to 20 doses of DMPA-SC), printed check-lists and job aids, and reporting forms.The community-based events, known as « campaign days » in DRC, were advertised throughout the communities and typically took place in the courtyard of health facilities to provide a modicum of privacy from the busy streets. Women who came to the campaign days expected the methods to be free and were first counseled as a group by students who presented the benefits of FP and the methods they could provide. The students then proceeded with the clients to chairs set around the courtyard  for individual counseling. After the client chose her method and was screened for eligibility, the student recorded the service data. For DMPA-SC clients, the student offered to train them to self-inject and if the woman was interested, demonstrated on a mannequin. Correct self-injection techniques were validated using a checklist and women declared skilled by the students were invited to self-inject and come back 3 months later for re-injection. The same campaign days were organized then, and women were again invited to practice self-injection. At the end of this second round, students provided the women they deemed competent with three doses of DMPA-SC to re-inject at home at 6, 9 and 12 months. The entire process was supervised by professors from the medical and nursing schools and personnel from the National Program for Reproductive Health (PNSR), who observed at least one interaction per student and provided immediate feedback to improve service quality. Visual privacy inside the courtyard of the health facility was non-existent, a common issue with healthcare provision in DRC, but the students were able to maintain audio privacy. In addition, although the facility was compensated to provide its courtyard, its staff did not participate in the event. Women who wanted an implant or IUDs were referred to the facility and had to pay the regular user fees. The students were not remunerated since these events are considered part of their practicum in the nursing schools curriculum. Each of the six target sites  organized three campaign days per round , for a total of 36 campaign days.The second pilot took place in two rural Health Zones of the Lualaba province. Community-health workers (CHWs) already involved in community immunization or nutrition programs were invited to participate in the pilot and trained for 6 days in FP counseling and methods provision, including DMPA-SC injections. After being deemed competent by the Health Zone authorities, the CHWs participated in campaign days organized at the main marketplaces (Fungurume and Bukenya) of the Health Zone. There, the CHWs installed a stand with signage advertising FP services and the full display of methods they offered. The market radio was also used to advertise the free services. Interested women were individually counseled for FP at chairs set around the stand and for those who were eligible and chose DMPA-SC, the CHWs took them behind a tarp cabin to perform the injection. Women were then invited to come back 3 months later to receive their second injection and given recommendations to visit the local health center in case of side effects. Women who wanted clinical methods, counseled but not offered by the CHWs, were also invited referred to the facility. All contraceptives and supplies  were provided by the local implementing partner for the project. Nurses from referral health facilities were dispatched to supervise the CHWs, ensuring appropriate counseling for the full range of methods and safe injection practices for women receiving DMPA-SC. Each of the two sites  organized 2 campaign days per round , for a total of 8 campaign days.2.2For both studies, DMPA-SC providers were interviewed at the end of the second round of the pilot (three-month follow-up) by data collectors trained by Tulane University and experienced in digital data collection for FP surveys. Interviewers collected socio-demographic information from CBDs and asked them to assess the training they received. Interviewers also asked the CBDs about their experiences with FP counseling, service provision and DMPA-SC injection, stock-outs, service statistics reporting, and the referral system.Most questions were similarly formulated across both cadres of providers; this analysis excludes questions specific to certain aspects of a given pilot .Data were collected using smartphones using the OpenDataKit (ODK) application. Frequencies and Chi2 significance tests were calculated using STATA18 to compare both groups' answers.3see. As expected, students were younger (25.6 years old on average) than the CHWs (42.3 years old), and they were more educated (only a third of the CHWs had completed high school). Also, the students were less likely to be married or live in union (13.2% for the students) and to have children than the CHWs (73.5%). Students were less likely to be employed (28.3%), compared to the CHWs (52.9% had a job outside of their FP activities). Gender distribution was more equal for the CHWs  than for the students three quarter of whom (73.6%) were female.The two cadres of providers (students and CHWs) differed significantly in terms of socio-demographic characteristics see. As expeBoth groups declared that the training had prepared them somewhat or very well to work as CBDs, but the students were slightly less satisfied with the amount of practice they had before starting DMPA-SC injections in the community. Two-thirds of students (67.9%) reported that they received “completely adequate” practice versus 79.4% of CHWs. Differences emerged between the two groups' requests for additional training. About 15.1% of the students felt they needed to be better trained in interacting with Health Zone authorities and clients, and service statistics reporting. However, the most significant differences (p=.00) were requests for additional training performing DMPA-SC injections, mentioned by 58.8% of the CHWs but only 9.4% of the students.After completing the training, the students and CHWs provided similar FP services . The han3Most CBDs across groups declared being somewhat or very comfortable with all aspects of FP service provisions at the community level, with 90.4% of the students and 79.4% of the CHWs feeling comfortable performing DMPA-SC injections.A majority of providers experienced stock-outs: 55.9% of CHWs and 71.2% of students ran out of at least one contraceptive during campaign days. With regards to DMPA-SC, the students were more likely to experience stockouts: 45.3% reported “sometimes or often” stockouts of DMPA-SC compared to 14.7% of CHWs (p=.00).Students (64.71%) were less likely to report that they received adequate supervision than RECOs (96.3%) (p=.03). Although 82.7% of CHWs, reported receiving individual visits from supervisors, 14.7% of them (n=5) found the supervision “not really” or “not at all” adequate. By contrast, in Lualaba, 91.2% of CHWs said they were supervised in person during their community distribution activities. Nearly all CHWs (93.8%) and 67.44% of the students found the supervision they received to be “very useful”.Significant differences also appeared between the cadres of providers in their practice of referring women to health facilities. Fewer students (82.7%) reported knowing which structures offered FP services they could refer women to than CHWs (100%) (p=.01). More students (15.1%) than CHWs (2.9%) reported that they would insist that their client accept one of the methods they offered, rather than referring women who wanted a clinical method  (p=.07). CHWs were more likely to refer women to a facility for management of side effects than the students . Overall(Data not shown in tables).When asked about perception of their FP activities in their own communities, students more frequently (76.9%) reported encountering resistances whereas only 41.2% of the CHWs indicated ever hearing open opposition (p=.00). However, all providers reported similar reasons for community resistance with two-thirds of them mentioning rumors surrounding family planning in general (namely increased risks for infertility and cancer incorrectly associated with contraceptive use) rather than their own work as CBDs. Finally, almost all providers were “satisfied” or “very satisfied” with their experience and most (100% of students and 88.2% of CHWs) would either “encourage” or “strongly encourage” their peers to work as a community-based FP providers” . 4Task-shifting sexual and reproductive health services (and particularly DMPS-SC provision) is a promising strategy for expanding access to contraception in resource-constrained environments CHWs in Lualaba were initially slightly more intimidated in performing injection, but they eventually reported it to be easy, as was counseling women for other contraceptive methods. The students, while understandably more comfortable with the clinical aspects of DMPA-SC provision, reported being less comfortable with group counseling and recruiting new clients, possibly because they were younger and more intimidated than the Lualaba CHWs, who had been involved in health-related service provision in the community before participating in the DMPA-SC pilot.Overall, difficulties encountered across all cadres of providers  were more likely to be related to issues beyond their control, rather than to DMPA-SC provision. The prevalence of stock-outs, particularly for the students facing high demand during the campaign days organized in Kinshasa's communities, is a reminder that contraceptive security, from procurement to last mile delivery, is a central issue to successfully scaling-up FP service delivery strategies.In addition, addressing gaps in the referral system, as providers reported not being completely comfortable on when and how to refer clients to fixed facilities is a key requirement to strengthen the task-shifting process. Keeping the community workers fully integrated and supported within existing health systems is crucial to guaranty the safety and sustainability of such programs This analysis had several limitations. Providers for both pilots were recruited based on their willingness to participate, their level of education, and their previous performance as either students or CHWs. Thus, these results represent a best-case scenario for task-shifting using these two cadres. In addition, these self-reported data likely reflect some social desirability bias. Finally, while international guidelines and research 5The similarities between the experiences and satisfaction of these two very different groups of providers complements the positive findings from acceptability and feasibility studies among the acceptors of DMPA-SC and key informant interviews among local health authorities.Following on the 2015 DMPA-SC pilot, the government is now institutionalizing FP training and community-level service provision among nursing schools in the DRC, while other projects are exploring the use of lay health workers to provide DMPA-SC. As these initiatives evolve, it will be necessary to conduct more systematic comparative studies between these different cohorts of providers to assess the quality of FP care delivered and to evaluate strategies for sustaining their commitment and effectiveness.


The purpose of this study was to retrospectively evaluate if a change in practice from January 2013 to August 2015 affected the rate of surgical-site infections following kidney transplantation at the single academic medical center. More patients were found to have a surgical-site infection when surgical antibiotics were only given intra-operatively despite a lower incidence of risk factors identified in the literature when compared to the cohort who received antibiotics intra-op and post-op for 24 hours. Kidney transplantation is a well-established and highly successful treatment for end-stage renal disease. In 2014, over 17,000 kidney transplants took place in the United States . MultiplThe risk of surgical-site infections related to immunosuppression may be affected by the intensity of immunosuppression, the receipt of these medications prior to transplant and certain agents pose a higher risk. The use of immunosuppressive medications prior to transplant is also a risk factor for surgical-site infections in kidney transplant recipients. Patients who receive more intense immunosuppressive regimens will likely be at a greater risk of developing a surgical-site infection. Mycophenolate mofetil (MMF) and mammalian target of rapamycin (mTOR) inhibitors are commonly used in maintenance therapy following a kidney transplant and are independent risk factors for surgical-site infections . In addiThere currently is no consensus on the optimal perioperative prophylaxis regimen for renal transplant surgery , 7. HoweSurgical-site infections may lead to higher treatment cost, possible re-admissions, increased antibiotic use, possible surgical procedures, and increased risk of Clostridium difficile . Less anPrior to April 2014, the standard practice at our institution was to administer cefazolin 1 g IV intra-operatively followed by cefazolin 1 g IV every eight hours for 24 hours, post-operatively. In April 2014, the protocol changed to administer a single dose of cefazolin 1 g IV intra-operatively, and to no longer administer surgical prophylaxis post-operatively. If the surgical procedure lasts longer than four hours, both protocols required that the patient be re-dosed with the appropriate antibiotic(s) intra-operatively. Patients with a penicillin allergy were administered an alternative agent. The choice of alternative antibiotic in penicillin-allergic patients was not standardized at the institution and instead, antibiotic choice was at the discretion of the anesthesiologist or surgeon. Regardless of the antibiotic chosen, the duration of surgical antibiotic prophylaxis remained the same in both protocols.The purpose of this study was to retrospectively evaluate if the change in practice affected the rate and classification of surgical-site infections following kidney transplantation at this single academic medical center.The primary objective of this study was to determine if the change in surgical antibiotic prophylaxis in kidney transplant patients affected the rate and classification of surgical-site infections in this patient population, using the Centers for Disease Control (CDC) National Nosocomial Infection Surveillance System (NNIS) definition for surgical-site infections Table  8]. The. The8]. This study was a retrospective review of an observational cohort of patients who received a kidney transplant at a single academic medical center. A senior researcher reviewed all patients for surgical-site infections. Two independent researchers did all chart reviews manually. A third reviewer was available to clarify any questions or discrepancies found.All recipients of a kidney transplant alone at the institution from January 1, 2013 to August 31, 2015 were eligible for inclusion. All recipients of any other organ at the same time as kidney transplant were excluded. Patients were divided into two groups: the Continuance group and the One-and-Done group. The Continuance group included 50 patients who received the historical surgical prophylaxis protocol of antibiotics given intra-operatively and continued for 24 hours post-operatively. The One-and-Done group included 50 patients who received one dose of antibiotics given intra-operatively only.A power calculation indicated that over 400 patients were required in each group to detect a significant difference . It was not possible to achieve a study population of this size at the single academic medical center within a reasonable time frame, as this center averages approximately 80–100 kidney transplants annually. Rather, the investigators sought to look at trends in the data available within the institution.The baseline characteristics of all patients included in this study are presented in Table Within the first 30 days post-transplant, zero deep incisional and organ space surgical-site infections were found. Eight superficial incisional surgical-site infections were identified, two in the Continuance group and six in the One-and-Done group . The overall infection rate in the Continuance group was 4% and 12% in the One-and-Done group. The risk factors present in patients with surgical-site infections are illustrated in Table When analyzing the cohort of patients with surgical-site infections further, four of the eight patients with surgical-site infections received surgical antibiotic(s) that were not part of the standard cefazolin regimens. The previously stated overall infection rate in Continuance group was 4% (2/50), and increased to 20% (1/5) if a non-cefazolin regimen was used. The overall surgical-site infection rate was 12% (6/50) in One-and-Done group, and increased to 30% (3/10) in patients who received a non-cefazolin regimen.The rate of surgical-site infections was also increased among those patients who received cefazolin 1 g compared to the overall surgical-site infection rate, in both cohorts. No surgical-site infections occurred in patients who received 2 g or more of cefazolin intra-operatively  Table .The choice of antibiotic prophylaxis among patients with surgical-site infections is presented in Table Fifty percent of patients (n = 4) with a surgical-site infection had a BMI greater than 27. The median BMI among patients without a surgical-site infection was 27.1 compared to 26.7 in those with a surgical-site infection.The differences among the use of immunosuppression prior to transplant and immunosuppressive regimen used during transplant for the Continuance group and One-and-Done are available in Table We predicted that the Continuance group would have a higher incidence of surgical-site infections because more literature-reported risk factors were present at baseline. However, this is not what was observed in this small cohort. More patients were found to have a surgical-site infection when surgical antibiotics were only given intra-operatively (One-and-Done group), despite a lower incidence of risk factors identified in the literature when compared to the cohort who received antibiotics intra-op and post-op for 24 hours (Continuance group). It is possible that the patients included in this small cohort have additional risk factors that have not been reported in the literature.Additionally, there was an increased incidence of surgical-site infections when a non-cefazolin based regimen was used. The majority of the non-cefazolin regimens used a single antibiotic, such as vancomycin 1 g or clindamycin 600–900 mg. This suggests that the use of a single non-penicillin regimen is insufficient to prevent surgical-site infections in this patient population and dual therapy should be used, as recommended by the guidelines Table . All theThe incidence of surgical-site infections increased when cefazolin 1 g was used in either group. However, when cefazolin 2 g or more was used, as recommended by the guidelines, no surgical-site infections occurred. This suggests that the increased incidence of surgical-site infections was more likely due to the cefazolin dose rather than the duration.When evaluating the impact of BMI on surgical-site infections, we expected that patients with a higher BMI would acquire more surgical-site infections, because a BMI greater than 27 is a literature-reported risk factor. In our study, the median BMI for patients with surgical-site infections 26.7) was below the median BMI for patients without surgical-site infections (27.1). It is possible that this reflected the small sample size of our study. However, 50% of patients with a surgical-site infection had a BMI greater than 27. BMI greater than 27 has been validated as an independent risk factor for surgical-site infections [.7 was bePatients with more intense immunosuppression and immunosuppression prior to transplant, were expected to acquire more surgical-site infections. Nearly 63% of the eight patients with surgical-site infections did receive antibody induction  is now the preferred regimen at out institution. Clindamycin in combination with levofloxacin is the preferred alternative regimen for use in penicillin-allergic patients. Less antibiotic exposure is advantageous because it can reduce the potential for resistant organisms, decrease health care costs and lessen the potential for toxicity. It also demonstrates the applicability of guideline-supported change in transplant, rather than a continuation of what has been perceived to work in the past. After looking at our data, we have the opportunity to standardize the dose to minimize surgical-site infections in the future.


The soil microbiota conducts important biological ecosystem functions, but the mechanism underlying community-environment interactions for soil microbiota remains unclear. By using two distinct soils for cross inoculation, we successfully simulated the assembly of the bacterial community in sterile soil. Thus, the reasons why inoculum and recipient have dominated community assembly in previous investigations are investigated in this study. We found that inoculated bacteria presided over environmental selection for community assembly due to the varied difference of ecological equivalent bacteria, either divergent or convergent. The significance of neutrality for the ecologically equivalent bacterial species that immigrated into the recipients should be emphasized in exploring the mechanisms of community assembly. Our finding is helpful for understanding the community-environment interaction, a basic question in ecology, and it would shed light on this issue that has perplexed scientists for many years. Exploring the assembly mechanism of microbiota is critical for understanding soil ecosystem functions. However, the relative importance of different biotic and abiotic factors in determining the bacterial community has not been properly clarified. In this study, the effects of inocula and recipients on the assembly of the soil community were investigated to evaluate their importance by inoculation experiments with sterile soil. Two distinct soils, conventional nitrogen-fertilized soil and aromatic-compound-contaminated soil, were sterilized, cross inoculated, and incubated for 2 months under different inoculation doses and oxygen conditions. The results showed that the greatest variation in community structure emerged in the samples inoculated with distinct inocula rather than in the samples of different soil recipients. The phylogenies in the two inocula were diverse and dissimilar, although there were many ecologically equivalent bacteria. When the inocula with dissimilar ecologically equivalent species were used, the assembled communities were primarily determined by the inocula as indicated by the beta diversity and variation partitioning analyses. In contrast, environmental selection dominated the process when ecologically equivalent species in the inocula were similar, as when only one type of inoculum was used, where the soil habitat selected the most adaptive bacteria from the defined inoculum pool. These results indicate that inoculated bacteria are dominant over environmental selection if they are sufficiently dissimilar, although the effect of environmental selection is more obvious when similar bacteria are inoculated in the soil for community assembly. Our findings suggest that the immigration of exotic bacteria could be a primary factor impacting community assembly.IMPORTANCE The soil microbiota conducts important biological ecosystem functions, but the mechanism underlying community-environment interactions for soil microbiota remains unclear. By using two distinct soils for cross inoculation, we successfully simulated the assembly of the bacterial community in sterile soil. Thus, the reasons why inoculum and recipient have dominated community assembly in previous investigations are investigated in this study. We found that inoculated bacteria presided over environmental selection for community assembly due to the varied difference of ecological equivalent bacteria, either divergent or convergent. The significance of neutrality for the ecologically equivalent bacterial species that immigrated into the recipients should be emphasized in exploring the mechanisms of community assembly. Our finding is helpful for understanding the community-environment interaction, a basic question in ecology, and it would shed light on this issue that has perplexed scientists for many years. The soil environment harbors the greatest bacterial diversity . These b3–4–The community-environment interaction has been extensively studied in community ecology . Some au9–12–However, other studies have reported that the role of biotic factors is more important for structuring the microbiota. According to the neutral theory, the influence of environmental factors on each species in the habitat is neutral and neither promotes nor inhibits change –20. Stoc–In general, inoculum and recipient dominated community assembly in previous investigations. However, the variability in all investigations has perplexed scientists and obscured community assembly mechanisms. From these varied conclusions arose the question of what is the relative importance of inoculum and recipient in the determination of community structure? To answer this question, in this study, we simulated the bacterial community assembly in soil by incubating microcosms of sterilized soil reinoculated with two distinct soil samples. The impacts of the inoculation dosage and aeration condition were also checked. After incubation, microbiota analyses were performed to determine the relative importance of inocula and recipient conditions when comparing all developed microbiota derived from the different soil inocula versus separately comparing the microbiota developed from each inoculum.−1 soil were obtained from the aromatic-contaminated soil (ACS) and optimized nitrogen-fertilized soil (ONS), respectively, before irradiation and decreased to 0.084 and 0.098 μg · g−1 after irradiation, thus confirming the strong lethal effect and denaturation of most of the DNA   and under high dissolved nitrogen (DN) consumption than under low DN consumption conditions .Bacterial growth in the inoculated samples was assessed by quantifying the total amount of DNA and the 16S rRNA gene copy numbers (see  U test)  and B. I U test)  and B. T10.1128/mSystems.00496-19.2TABLE S1Table S1, PDF file, 0.1 MB.Quantity of DNA and number of 16S rRNA gene copies in different treatments. Download Copyright © 2019 Wu et al.2019Wu et al.Creative Commons Attribution 4.0 International license.This content is distributed under the terms of the A total of 4,214,140 quality-controlled sequences for the amplicons of the amplified V3-V4 region of the 16S rRNA gene were obtained . These sequences were clustered into 5,338 OTUs  (97% similarity). Rarefaction and Shannon diversity curves revealed that the ONS-inoculated samples had higher diversity  than the ACS-inoculated samples see  and B. T10.1128/mSystems.00496-19.1FIG S1P < 0.0001. (E) Venn diagram of the OTU distribution between two groups of differently inoculated samples. Download FIG S1, TIF file, 3.0 MB.Bacterial alpha diversity of the soil samples. (A) Rarefaction analysis. Repeated sampling of OTU subsets was used to evaluate where further sampling would likely yield additional taxa, as indicated by whether the curve has reached a plateau value. (B) Shannon diversity index curves to estimate the diversity of taxa present in individual soil samples. (C) Comparison of observed OTUs between ONS-inoculated samples and ACS-inoculated samples. (D) Comparison of the Shannon diversity index between ONS-inoculated samples and ACS-inoculated samples. The Mann-Whitney U test (nonparametric test) was used to analyze the variation between two groups. ****, Copyright © 2019 Wu et al.2019Wu et al.Creative Commons Attribution 4.0 International license.This content is distributed under the terms of the 10.1128/mSystems.00496-19.3TABLE S2Table S2, PDF file, 0.1 MB.Alpha diversity indices of different treatments after incubation for 2 months. Download Copyright © 2019 Wu et al.2019Wu et al.Creative Commons Attribution 4.0 International license.This content is distributed under the terms of the However, the inoculum was another factor that contributed to the taxonomic structuration of the soil microbiota that developed in the soil microcosms, as evidenced by the significant differences in the MANOVA between the ONS- and ACS-inoculated samples detected by the unweighted UniFrac PCoA plots for the OTUs . The resActinobacteria, particularly representatives of Nocardioidaceae and Streptomycetaceae, which were found at higher quantitative levels than those observed in the controls, regardless of the inoculum used. When the microcosms were incubated under anaerobic conditions, the proportions of Firmicutes and Proteobacteria increased significantly, with a particularly significant increase in representatives of Halomonadaceae  in the samples with the ONS samples being used as inoculum and a prevalence of Micromonosporaceae (Actinobacteria) for these samples in which the ACS was used as inoculum  and OTU17 (Ohtaekwangia), which were specifically enriched by the combination of ONS as the donor and recipient (H-ONS-rONS-ae and L-ONS-rONS-ae) , and OTU11 (Kribbella), which was enriched by the combination of ONS as the donor and ACS as the recipient (H-ONS-rACS-ae and L-ONS-rACS-ae). The relative abundance of OTU_3  depended on a recipient soil with a higher proportion of ACS (H-ONS-rACS-an and L-ONS-rACS-an) than ONS (H-ONS-rONS-an and L-ONS-rONS-an). Several OTUs were positively quantitatively influenced by the recipient soil when the ACS inoculum was used, including OTU1 (Nocardioides) and OTU11 (Kribbella), which were enriched in H-ACS-rACS-ae and L-ACS-rACS-ae. OTU94 (unclassified Kitasatospora), OTU4 (Streptomyces), and OTU17 (Ohtaekwangia) were enriched in H-ACS-rONS-ae and L-ACS-rONS-ae. OTU3  was more abundant in H-ACS-rACS-an and L-ACS-rACS-an. OTU2 (unclassified Janibacter) was enriched in H-ACS-rONS-an and L-ACS-rONS-an  shaped by several key soil environmental variables. Bacterial communities were well separated by RDA1 (24%) according to the major variable oxygen condition and by RDA2 (22%) according to the major variable inoculum. However, RDA did not show clear clustering of the soil samples based on the recipient soils.Redundancy analysis (RDA)  assessedP < 0.001), followed by oxygen availability . The characteristics of the recipient soil, including the type of recipient soil, explained 9.5% of the observed variation (P < 0.001), followed by the inoculum density (dosage) .A variation partitioning analysis (VPA) was performed to calculate the relative contributions of the inoculum (type and dosage), oxygen, and recipient basic soil characteristics on the taxonomic composition of the bacterial community after 2 months of incubation . These vGp4 and Gp6. The 21 OTUs enriched in the ACS-inoculated samples were affiliated with 18 different genera, with the 3 OTUs with the highest abundance belonging to Pseudomonas.The RDA approach was used to identify the OTUs driven by the inoculum and to determine the main contributor to the establishment of the community structure in the incubated soil samples  and C. UDyadobacter), OTU5094 (unclassified Phytohabitans), OTU4024 (unclassified Promicromonospora), OTU4151 (unclassified Actinosynnema), OTU1177 (unclassified Citricoccus), OTU13 (Promicromonospora), OTU59 (Nocardia), OTU1651 (Saccharothrix), OTU70 (Pseudonocardia), OTU3050 (unclassified Aeromicrobium), OTU156 (unclassified Aciditerrimonas), OTU86 (unclassified Luteimonas), OTU395 (Ohtaekwangia), OTU125 (Aliidiomarina), OTU15 (unclassified Fervidicella), OTU1610 (Cellulomonas), OTU103 (unclassified Pelotomaculum), OTU94 (unclassified Kitasatospora), OTU1372 (unclassified Marmoricola), OTU72 (unclassified Azonexus), and OTU117 (Cupriavidus)  similarly regardless of the recipient soil. Furthermore, among the OTUs correlated with the inoculum factor, most were abundant in the initial inoculum , whereas few of them were rare . All of these OTUs were enriched after incubation, and some became predominant after incubation, including OTU74 (iavidus)  and D.The soil bacterial community structure was primarily impacted by the inoculum. However, differences were also detected when the same inoculum was used to seed different soils, indicating that differences in soil physical and chemical properties also influenced the growth of some bacteria. OTUs that were specifically impacted by the recipient ONS (rONS) and ACS (rACS) soils were identified using RDA . When onIdentifying the mechanisms by which bacterial communities are generated and maintained in the soil is essential for understanding the biological functions of soil . Numerou24–First, well-designed experiments are necessary to determine the reasons for the variation existing in the explanation of the role of inoculum and environment selection in community assembly. For this purpose, the completeness of the sterility of the recipient soil is an important issue to truly reflect microbial community assembly in the inoculated soil microcosms. In our study, the absence of bacterial and fungal colonies on solidified media after plating diluted irradiated soil subsamples as well as the constant decrease in extracted DNA during incubation of the control microcosms confirmed the effectiveness of the soil sterilization and excluded any bias due to the persistence of surviving cells in the recipient soils. The results also showed that the 2-month incubation time permitted the restoration of a bacterial biomass that was at least quantitatively similar to that estimated in the original soils or in the nonirradiated controls, confirming the development and assembly of a new bacterial community.According to the perspective of microbial biogeography, the dispersal of microorganisms is limited, and the local species pools in different habitats are dissimilar , 29, 53.Gaiella) in the ONS inoculum have been reported to possess aromatic- and organic-compound-degrading functions or were detected in sites polluted with aromatic and organic compounds (Promicromonospora), OTU15 (unclassified Fervidicella), and OTU59 (Nocardia). Some of the rare OTUs multiplied rapidly to become predominant in the newly developed soil bacterial communities. We speculate that these rare bacteria were predominant in the history of the source community. The development of equivalent species in the recipient soils led to a significant correlation of the community structure with the inoculum, the most important factor shaping the bacterial community structure. Clearly, when dissimilar ecologically equivalent species immigrated into the recipient soils, they survived or were enriched in sterile environments. Even if the recipient soils were the same, the dissimilar equivalent species provided by the different inocula resulted in distinct community structures. Therefore, the effect of the inoculum on the community structure profile was obvious, and the immigration of equivalent species dominates community assembly in different recipients . These species survived and colonized similarly in an agricultural soil and a telluric environment contaminated by aromatic compounds. For example, 35 genera from the ACS inoculum are known to be common and abundant agricultural soil colonizers . In that situation, the finite ecologically equivalent species would occupy corresponding niches in both recipients; however, other nonequivalent species in the inoculum would be differentially selected by the physical and chemical properties of the recipient soils; thus, the niche-adapted bacteria would be selected from the inoculum , 24. TheAccording to our results, we found that the community structures are shaped by multiple factors  . The finIn conclusion, we distinguished the relative importance between inoculum and recipient environment in the determination of community structure. We found that inoculum was more important in the process of community assembly. Our investigation also explained the reason for the variability in previous studies about the role of biotic factors and environmental selection. Discrepancy in the determinative factors for community assemblies was associated with the differences between inocula that contained either similar or dissimilar ecological equivalent bacteria. On the basis of the results of our study, we may deduce that once the sources of inoculated bacteria are homologous and their compositions are similar, environmental selection would dominate the assembly processes. If inoculated bacteria are heterologous and phylogenetically dissimilar, they would dominate over the selection effect of environmental conditions. Here, we touched upon the basic and eternal ecological topic about the community-environment interaction. Speculatively, the types of inocula impact the community-environment interactions and thus act as the most important factor for the community assembly. The similarity between inocula is also important for the assembly of the bacterial community. In extreme situations, the inocula have totally different or identical bacteria, as the cases of our experiment with two type of distinctly different inocula or only with one type of inoculum  and C. HHowever, soils are complex environments that dictate the use of artificial conditions to address these questions. The use of sterilized soil microcosms that are artificially reinoculated and incubated under lab conditions is far from a simulation of natural conditions. Therefore, other approaches are required to verify the conclusions drawn in this study. Nevertheless, by using cross inoculation with two distinct soils, we explored the relative importance of inoculum and recipient during community assembly and revealed the reason for the variability in the explanation of the role of these factors. This study would be a step forward toward realizing the prediction and manipulation of the composition and dynamics of naturally occurring microbial communities, which would be beneficial to engineering, medical, agricultural, and environmental science.4+-based fertilizers are the most commonly applied nitrogen fertilizers (Two different types of soil were used in this investigation. One was sampled from cultivated farmland with optimized nitrogen fertilization with straw management (optimized nitrogen fertilized soil [ONS]) at a cropland in Quzhou , Hebei Province, northern China. The field at this sampling site consists of intensively managed agricultural soils, where a winter wheat-summer maize rotation is the dominant crop production system and urea- and NHtilizers . The soitilizers . The twotilizers .After the soil samples were sieved, both subsamples were sterilized by gamma irradiation , and the irradiated soil samples were stored as in reference DNA was extracted from 0.5 g of soil as described previously , 36. EacThe extracted DNA was used as the template to amplify the V3-V4 region of the 16S rRNA gene to construct the sequencing library. The library was constructed according to the manufacturer’s instructions  with somq value  of less than 20. If a pair of reads had a minimum overlap of 50 bp, they were merged into a complete read, which was retained only if it was longer than 399 bp, and the expected error was no more than 1  for rarefaction to equalize the differences in sequencing depth using QIIME . RepreseP < 0.05). Statistical significance was assessed by the Monte Carlo permutation procedure (MCPP) with 9,999 random permutations under the full model. Variation partitioning analysis (VPA) was performed to partition the total variation of the dependent variable into various portions as described by Xun et al.  with MATLAB 2014a  as described by Xu et al.  and TongThe data on natural ONS and ACS samples have been reported in reference SRP153935.The 16S rRNA gene sequences in this study were submitted to the GenBank Sequence Read Archive (SRA) database in the National Center for Biotechnology Information (NCBI) under accession number


Prior to goal-directed actions, somatosensory target positions can be localized using either an exteroceptive or an interoceptive body representation. The goal of the present study was to investigate if the body representation selected to plan reaches to somatosensory targets is influenced by the sensory modality of the cue indicating the target’s location. In the first experiment, participants reached to somatosensory targets prompted by either an auditory or a vibrotactile cue. As a baseline condition, participants also performed reaches to visual targets prompted by an auditory cue. Gaze-dependent reaching errors were measured to determine the contribution of the exteroceptive representation to motor planning processes. The results showed that reaches to both auditory-cued somatosensory targets and auditory-cued visual targets exhibited larger gaze-dependent reaching errors than reaches to vibrotactile-cued somatosensory targets. Thus, an exteroceptive body representation was likely used to plan reaches to auditory-cued somatosensory targets but not to vibrotactile-cued somatosensory targets. The second experiment examined the influence of using an exteroceptive body representation to plan movements to somatosensory targets on pre-movement neural activations. Cortical responses to a task-irrelevant visual flash were measured as participants planned movements to either auditory-cued somatosensory or auditory-cued visual targets. Larger responses  were found when participants planned movements to somatosensory vs. visual targets, and source analyses revealed that these activities were localized to the left occipital and left posterior parietal areas. These results suggest that visual and visuomotor processing networks were more engaged when using the exteroceptive body representation to plan movements to somatosensory targets, than when planning movements to external visual targets. In a game of “Simon Says”, spoken instructions such as “touch your elbow” can prompt movements towards a specified body location. Similarly, the feeling of a mosquito landing on the elbow could also prompt movements to this same position. Although the goal of both actions is to reach to a common body location , the manner in which this position is identified could influence the body representation used to determine the target’s coordinates. The purpose of the present study was to examine if the modality of the stimulus indicating a somatosensory target’s position influences the body representation used to plan movements.Evidence that movements to somatosensory targets could be planned using multiple representations is drawn from studies of autotopagnosia, a rare nervous system disorder characterized by the inability to localize and orient one’s own body parts –3. In a It is difficult to determine if the use of different body representations in patients with autotopagnosia emerges as an adaptation to their neurological impairment, or if this context-dependent selection of a body representation for movement planning also occurs in healthy individuals. In the present study, we sought to examine the contribution of the exteroceptive and interoceptive body representations to sensorimotor transformations during motor planning in healthy individuals by evaluating reaching movements towards somatosensory targets cued by simple auditory and vibrotactile stimuli.In Experiment 1, to examine the body representation and sensorimotor transformations used to prepare movements to somatosensory targets, we asked participants to reach to somatosensory targets while looking at either a central fixation point or a peripheral fixation point . ReaAlthough there is evidence for flexibility in the encoding of somatosensory targets , 14, it Ten participants  volunteered for the experiment. All participants were right-handed with normal or corrected-to-normal vision. The experiment took 1.5 hours to complete. Informed consent was obtained prior to the beginning of the experiment and the local research ethics committee at Aix-Marseille University approved all procedures. The protocols and procedures employed were in accordance with the 1964 Declaration of Helsinki.A depiction of the experimental setup is presented in The aiming apparatus was also equipped with a microswitch positioned 32 cm directly in front of the participant. The switch was used as the starting position for the reaching finger. Three piezoelectric buzzers  were positioned 25 cm to the left of the microswitch and ~ 55 cm away from the participant. The input to the buzzers was adjusted using potentiometers to produce a loud , a medium , or a soft  sound, which identified the target in the auditory-cued conditions (see below).Three circular indentations were made between the participant and the microswitch, at 15.5 cm, 15 cm, and 16.5 cm from the microswitch see  and -3.5Fixation positions and visual targets  were projected onto the aiming surface using a custom MATLAB program  and Psychtoolbox-3 . Three fA white light emitting diode  attached to the participant’s right index finger was visible through the semi-reflective glass and provided visual feedback of the initial fingertip position in the visual-target condition (see below). Also, a black plastic shield was placed beneath the glass surface to occlude vision of the limb during the aiming movement. The position of the occluding surface was adjusted for each participant such that they could see the illuminated LED on their finger when it was at the home position.Eye positions were monitored with electro-oculography (EOG) , sampled at 1000Hz. The position of the index finger was tracked using an electromagnetic sensor secured to the tip of the right index finger , sampled at 100 Hz.Overall, the participants’ task was to maintain gaze fixation while performing accurate reaching movements with the index finger of the right hand to targets located between the home position and their body. Multiple target locations were included to introduce variable movement parameters to each reaching trajectory. This variability was introduced to reduce the likelihood that participants engaged in sensorimotor processes related to target position encoding before the onset of the imperative stimulus. Participants reached to somatosensory targets in response to either an auditory (AUD-SOMA) or a vibrotactile (TACT-SOMA) cue. To obtain reference values for gaze-dependent reaching errors, participants also performed reaches to visual targets in response to an auditory cue (AUD-VIS). The presentation order of these conditions was counterbalanced across participants.In the AUD-VIS condition, participants positioned their left hand in a comfortable position, either on their lap or on the table surface to the left of the aiming apparatus. The trial sequence was initiated once the participant depressed the home position microswitch with their right index finger. This action triggered the illumination of the finger LED and the presentation of the current fixation point . Two seconds later, participants were presented with a soft, medium, or loud sound. For half of the participants, the loud and soft sounds corresponded to the right and left targets, respectively. This correspondence was reversed for the other half of the participants. At movement onset, the finger LED was extinguished, therefore participants only saw the position of their reaching finger relative to the visual target prior to reaching.The AUD-SOMA condition was similar to the AUD-VIS condition. But instead of visual targets, participants placed the three middle fingers of their left hand  into the three circular indentations beneath the plastic casing to serve as the somatosensory targets. The same auditory cues as in the AUD-VIS condition indicated the target finger positions. Participants were instructed to “aim to the perceived position of their fingernail as if it was projected onto the surface of the plastic case”. In contrast to the AUD-VIS condition, participants did not receive visual information about the position of their reaching hand prior to movement initiation.The TACT-SOMA condition was similar to the AUD-SOMA condition, except that a vibrotactile stimulus indicated the target finger . Similar to the auditory stimulation in the auditory-cued conditions, the tactile stimulation of the target finger occurred 2 s after the participant depressed the microswitch .Before each experimental condition, participants performed 2 sets of familiarization trials. For the AUD-VIS and AUD-SOMA conditions, the first set of familiarization trials consisted of 3 blocks of 3 reaching trials, wherein the same auditory-cue was presented in each block . Subsequently, participants performed 1 block of 15 trials, wherein auditory cues were presented in random order. After each trial in this familiarization block, participants were asked to report which auditory cue had been presented  and they were very accurate at distinguishing between the three different levels of sound . Participants were also presented with 2 sets of familiarization trials in the TACT-SOMA condition. Auditory cues were replaced by brief tactile stimulation applied to the reaching finger. The participant’s task in the second set of familiarization trials was to report which target finger had been stimulated and participants were all perfectly accurate in this task.In all experimental conditions, participants performed 10 trials in each fixation-target combination  for each of the 3 cue-target conditions  yielding a total of 270 total experimental trials.Only data from movements to the centre target were analyzed because gaze-shifts were equidistant with respect to this target  and a consistent sound level  was used to signal the target position across conditions. All finger and eye movement recordings were exported to custom software  and processed offline. Raw EOG traces were used to verify participants eye positions for each reaching conditions and trials wherein the participants failed to maintain their fixation position prior to or during the movement were removed. In addition, trials where participants perceived the incorrect sound, or where reaction times (RT) or movement times were higher or lower than 2.5 times the within condition standard deviation were also excluded from the analyses. Overall, less than 9% of trials (centre target) were excluded . Statistical analyses were performed with the Statistical Package for Social Scientists . Post-hoc comparisons were performed using R .Normalized directional reaching errors, reaction times (RTs) and movement times (MTs) were computed to investigate the effect of peripheral fixation on movement performance. Directional reaching error was defined as the angular difference (in degrees) between the home-target position vector and the home-movement end position vector. We used the within-participant mean and standard deviation computed in the centre fixation position to calculate a population z-score value for each trial with left and right gaze fixation. This normalization procedure therefore resulted in values that reflected the participant’s change in performance in response to a peripheral gaze shift relative to their own variability in the central fixation  condition. Negative and positive z-score values indicate movements biased to the left and right of the centre position, respectively.Reaction time was defined as the time that elapsed between the onset of the go signal  and the release of the home position microswitch. Movement time was defined as the time that elapsed between the release of the home position microswitch and movement end, which was defined as the first sample at which the instant velocity of the fingertip fell below 30 mm/s.t-tests with the Bonferonni correction. Additionally, for directional reaching errors, one-sample t-tests were used to examine if peripheral fixation yielded a significant bias  for each fixation direction, effect sizes for the one-sample t-tests were reported using Cohen’s d.Normalized directional reaching errors were submitted to a 2-fixation direction  x 3 cue-target condition  repeated-measures ANOVA. Reaction times and movement times were submitted to separate 3-fixation direction  x 3 cue-target condition  repeated-measures ANOVAs. The alpha level was set at 0.05 for all statistical contrasts, and effect sizes for the ANOVAs were reported as partial eta squared. Post-hoc tests for any significant interactions were completed using pairwise F = 64.7, p < 0.001 ηP2 = 0.89) and a significant interaction between fixation direction and cue-target condition  = 5.1, p = 0.018, ηP2 = 0.36). Critically, decomposing the interaction  revealed that the differences in gaze-dependent errors for the left and right fixation directions were higher in both the AUD-SOMA , and AUD-VIS target conditions , compared to the TACT-SOMA condition . Furthermore, one sample t-tests revealed that the magnitude of the directional reaching errors in both left and right fixation conditions in the AUD-SOMA (left: t(9) = 4.2, p = 0.024 d = 1.3; right: t(9) = -4.1, p = 0.003, d = 1.3) and AUD-VIS conditions (left: t(9) = 2.7, p < 0.001, d = 0.9; right: t(9) = -4.0, p < 0.001, d = 1.3) were significantly greater than zero. In contrast, normalized directional reaching errors for the left and right fixation directions in the TACT-SOMA condition were not significantly different than zero (left: t(9) = 1.8, p = 0.099, d = 0.6; right: t(9) = -1.5, p = 0.170). These results provide evidence that gaze-dependent coding was used for sensorimotor transformations when movements were performed to auditory-cued visual and auditory-cued somatosensory targets  = 19.1, p < 0.001, ηP2 = 0.68) indicating shorter reaction times in the TACT-SOMA (M = 471 ms SD = 87 ms) condition than in both the AUD-VIS  and AUD-SOMA  conditions. The ANOVA also revealed a significant condition by fixation interaction  = 3.7, p = 0.019, ηP2 = 0.27). The decomposition of the interaction indicated that changes in gaze direction significantly increased reaction times in the AUD-SOMA condition. More specifically, post-hoc tests revealed that, in the AUD-SOMA condition, RTs were significantly longer when participants shifted their gaze to the right  compared to when they fixated on the centre position. Mean RT was also 36 ms longer in the left fixation condition  than in the centre fixation condition, but this increase of RT fell short of statistical significance (p = 0.062). For both the AUD-VIS and TACT-SOMA conditions, the RTs were not significantly different between any of the fixation conditions. In addition, no significant differences in RT were found between the centre fixation conditions between the AUD-VIS and AUD-SOMA conditions. Finally, the analyses of MTs yielded no significant effects of fixation direction or cue-target condition, and no significant interaction between these factors .Analyses of the RTs revealed a significant effect of cue-target condition . This rIn Experiment 1, participants showed gaze-dependent endpoint errors when reaching to somatosensory targets cued by auditory stimuli. This result was attributed to the use of an exteroceptive, visually-based, body representation when reaching to somatosensory targets. The purpose of Experiment 2 was to examine the neural mechanisms associated with the gaze-dependent encoding of somatosensory target positions during movement planning.Although behavioural evidence for the remapping of somatosensory targets onto a gaze-dependent reference frame has been reported e.g. –15), the, the15])To test these predictions, the cortical response to a task-irrelevant visual stimulus  was measured as participants planned movements to both auditory-cued visual and auditory-cued somatosensory targets. Because baseline neural activity in the extrastriate cortex is a marker of visual processing, and the amplitude of visually-evoked responses increases along with baseline activity , 41, comTen participants , who did not participate in Experiment 1, were recruited for Experiment 2. All participants self-reported being right-handed and had normal or corrected-to-normal vision. Informed consent was obtained prior to data collection and a local ethics committee at Aix-Marseille University approved all procedures. The protocols and procedures employed in this experiment were in accordance with the 1964 Declaration of Helsinki. In total, the experiment took place over 2 sessions lasting 1.5 to 2 hours each. There was at least 1 but no more than 10 days between sessions (average = 4 ± 3.5 days).To accommodate the use of electroencephalography (EEG) and reduce electrical noise, all visual stimuli were generated using LEDs positioned on the aiming surface see  instead Three orange LEDs were placed at the same positions as the circular indentations that served as the somatosensory target position in Experiment 1. These LEDs were used as visual targets in the AUD-VIS condition. To prevent participants from receiving tactile feedback when reaching to visual targets, a thin piece (39 cm x 9 cm x ~0.3 cm) of translucent laminated Bristol board was placed over the LEDs. In addition, the participant’s right index finger was equipped with two LEDs: the same white LED that was used in Experiment 1 to indicate the initial position of the pointing finger, and a green LED  attached to the fingernail which was used to generate the stimuli for the VEPs.In contrast to Experiment 1, no gaze-shift stimulus was presented prior to the reaching movement. As the purpose of Experiment 2 was to evaluate the differences in cortical network activation underlying reaches to auditory-cued somatosensory and visual targets, it was critical that visual stimulus was presented in the same retinal location prior to the start of the reaching movement.Each trial began when one of the three possible fixation positions was illuminated. Participants looked at the fixation LED and placed their right index finger onto the corresponding microswitch see . As in EOnly one cue-target condition was used per experimental session (AUD-VIS or AUD-SOMA), and the presentation order of the target modality was counterbalanced across participants. As in Experiment 1, the sound-target mapping was counterbalanced between participants and remained the same for both experimental sessions. Movements were also conducted in darkness such that participants had no visual feedback of the reaching limb during the movements.In the AUD-VIS condition, when participants placed their finger on the home position microswitch, the finger and all target LEDs were illuminated. When participants released the microswitch to begin their reaching movement, the finger LED was extinguished, but all target LEDs remained illuminated throughout the trajectory. Therefore, participants could get terminal feedback about their movement accuracy through the reflection of the illuminated targets on their reaching finger. In contrast to Experiment 1 where gaze-dependent reaching endpoint errors were assessed, the difference in endpoint error between conditions was not relevant to the purpose of Experiment 2; thus, participants were allowed to have terminal feedback in both conditions.In the AUD-SOMA condition, participants performed reaches to the fingernail of one of the three middle fingers on their left hand. As in the Experiment 1, participants did not receive visual feedback of their reaching finger during movement planning. Participants also had terminal feedback in the AUD-SOMA condition as they made physical contact with the target finger.The magnitude of VEPs varies considerably between participants . For thFor the AUD-VIS control condition, when the microswitch was depressed, the finger and target LEDs were illuminated. Two seconds later, one of the three sounds was presented . This sound was followed, 100 ms later, by the 50 ms flash of the green LED. Participants remained on the home position until the fixation stimulus was turned off . The same trial procedure was used for the AUD-SOMA control condition, except that the participants placed the middle fingers of their right hand on the somatosensory target position and the reaching finger and target LEDs were not illuminated. As in the AUD-VIS condition, the green LED was flashed (for 50 ms) 100 ms after the presentation of the auditory stimulus.EEG data were recorded continuously from 64 pre-amplified Ag-AgCl electrodes  embedded in an elastic cap mapped to the extended 10–20 system. Two electrodes, a Common Mode Sense (CMS) active electrode and a Driven Right Leg (DRL) passive electrode specific to the Biosemi system, served as a feedback loop driving the average potential of the measured signal to levels as close as possible to the analog-to-digital converter reference voltage. EOG was recorded bipolarly with surface electrodes placed near both outer canthi as well as under and above the orbit of the right eye. EOG recordings were used to identify ocular artefacts (see below) and also allowed the experimenters to verify that participants fixated on the fixation LEDs during movement planning and execution. The EEG and EOG signals were digitized  and band-pass filtered . As in Experiment 1, kinematic data of the reaching finger were recorded by tracking the positions of an electromagnetic sensor fixed on the top of the index finger and sampled at a rate of 100 Hz.VEPs were obtained by averaging the time-locked EEG signals with respect to the onset of the 50 ms green flash (-200 to +300 ms). These epochs were averaged for each participant and for each condition. The mean amplitude of the -200 ms to -5 ms segment of each epoch served as the pre-stimulus baseline. The monopolar recordings were referenced to the average of the right and left mastoid electrodes. Recordings were visually inspected and epochs with eye movements or artefacts were rejected. The average number of traces used for each condition varied from 172 to 179 (out of a possible 180), and there were no significant differences between the amount of trials rejected between conditions as revealed by a 2 phase  by 2 cue-target condition (AUD-VIS and AUD-SOMA) repeated-measures ANOVA. The result of this analysis indicates that the signal-to-noise ratio was not different across conditions.A current source density (CSD) analysis was employed to increase the spatial resolution of EEG signals –47. The CSD-VEPs that were computed from the left posterior-occipital and left occipital-parietal electrodes sites  were used for the main analyses. These were chosen based on previous studies which implicated the underlying cortical areas in sensorimotor transformation processes and the use of the exteroceptive body representation ,52–55.2 transformation to account for the nonlinearity of ratios. Normalized CSD-VEP amplitudes were then used for statistical contrasts. An increase in normalized CSD-VEP amplitude was considered indicative of additional visual processing in the experimental condition relative to the control condition during the early stages of movement planning.CSD-VEPs were assessed, for each electrode, by measuring the peak-to-peak amplitude between the first positive (~100 ms) and negative (~150 ms) deflections after stimulus onset that could be identified in all participants and conditions see . The latThe neural sources of the P100-N150 in all experimental and control conditions were estimated using minimum norm technique as implemented in the Brainstorm software suite . To resoz.Both behavioural temporal measures  as well as normalized CSD-VEP amplitudes were submitted to paired samples t-tests. Effects sizes were reported with Cohen’s dt(9) = -0.1, p = 0.894, dz = 0.04). There were also no statistically significant differences in reaction times  = -2.2, p = 0.063, dz = 0.7). The latter observation suggests that, despite a tendency towards greater RT in the AUD-SOMA condition, the timing of the VEP stimulus presentation relative to the motor planning process was not significantly different between both conditions.Overall, there were no significant differences between any behavioral variables related to the temporal aspects of movement performance between the AUD-VIS and AUD-SOMA conditions. Paired samples t-tests did not reveal significant differences in movement times  were significantly larger (t(9) = 3.2, p = 0.053, dz = 0.7) than those observed in the AUD-VIS condition . VEP amplitude differences were also found at the PO7 electrode (t(9) = 3.2, p = 0.017, dz = 1.0), as the amplitude of the P100-N150 component was larger when planning movements in the AUD-SOMA condition  as compared to the AUD-VIS condition . In contrast, there were no significant CSD-VEP differences at the PO3 electrode (t(9) = -0.39, p = 0.702, dz = 0.13).Evidence for an increase in visual information processing during movement planning was found for reaches to auditory-cued somatosensory targets compared to auditory-cued visual targets in both the occipital O1: see  and occiIn Experiment 2, the cortical response to a task-irrelevant visual stimulus was measured as participants performed reaches to both auditory-cued visual and auditory-cued somatosensory targets. Overall, the results of both the CSD and source analyses revealed that participants had a greater response to visual inputs in when reaching to auditory-cued somatosensory vs. visual targets. These findings are consistent with the hypothesis that visual remapping of somatosensory target positions employs cortical networks associated with visual processing and visuomotor transformations.The increased sensitivity of occipital networks to visual inputs may be linked to a re-weighting of sensory information prior to engaging in higher-order computations. Occipital cortical areas have been implicated in early multisensory integration processes  during It should be noted that the results of the present study do not necessarily support a disengagement of the occipital cortex and PPC when planning movements to auditory-cued visual targets. Rather, the results of the present study suggest that planning movements when vision of the reaching hand and target is available does not require additional processing from areas sensitive to visual inputs compared to the control condition, at least at the time when the visual probe was presented .In summary, we found that the sensory modality employed to identify the position of a somatosensory target impacts the body representation used for movement planning processes. Preparing reaching movements towards auditory-cued somatosensory targets prompted the use of an exteroceptive representation of the body. By measuring the cortical response to a visual stimulus presented during movement planning, we also found that the additional sensorimotor transformation processes involved in the visual remapping of somatosensory target positions were associated with increased visual processing in occipital and posterior parietal areas. Taken together, the findings of the present study suggest that the sensorimotor transformation processes underlying movements to somatosensory targets derived using an exteroceptive body representation recruits visual and visuomotor cortical networks.


However, a mechanistic understanding of the Ag+ interactions with gold has been controversial. Reported herein is a systematic study of the Ag+ binding to AuNPs using several in-situ and ex-situ measurement techniques. The time-resolved UV-vis measurements of the AuNP surface plasmonic resonance revealed that the silver adsorption proceeds through two parallel pseudo-first order processes with a time constant of 16(±2) and 1,000(±35) s, respectively. About 95% of the Ag+ adsorption proceeds through the fast adsorption process. The in-situ zeta potential data indicated that this fast Ag+ adsorption is driven primarily by the long-range electrostatic forces that lead to AuNP charge neutralization, while the time-dependent pH data shows that the slow Ag+ binding process involves proton-releasing reactions that must be driven by near-range interactions. These experimental data, together with the ex-situ XPS measurement indicates that adsorbed silver remains cationic, but not as a charged-neutral silver atom proposed by the anti-galvanic reaction mechanism. The surface-enhanced Raman activities of the Ag+-stained AuNPs are slightly higher than that for AuNPs, but significantly lower than that for the silver nanoparticles (AgNPs). The SERS feature of the ligands on the Ag+-stained AuNPs can differ from that on both AuNPs and AgNPs. Besides the new insights to formation mechanism, properties, and applications of the Ag+-stained AuNPs, the experimental methodology presented in this work can also be important for studying nanoparticle interfacial interactions.A series of recent works have demonstrated the spontaneous Ag Gold nanoparticles (AuNPs) are among the most studied nanomaterial owing to their unique photochemical properties and their applications in biosensing, catalysis, biomedicine, electronics, and surface-enhanced Raman spectroscopy (SERS)  Ag+ induces desorption of the soluble organothiols that are initially anchored onto the AuNPs.Indeed, electrolyte binding to AuNPs should be studied with measurement strategies capable of differentiating ionic species directly absorbed on the surface and those confined within the electrolyte double layer or diffuse in the bulk solution. We recently reported the spontaneous adsorption of Ag+ adsorbed onto gold surface remains as a cation and not as a charge-neutral silver atom. In this study, we use the dialysis-purified and citrate-reduced AuNPs, instead of the AuNP aggregates or planar gold film as the model gold substrate. The dialyzed AuNPs maintain their dispersion stability in solution, as does the monolayer Ag+-functionalized AuNPs. This enabled us to investigate the effect of Ag+-staining on the AuNP charge states through zeta-potential titration and time-dependent zeta potential measurement. Further, by taking advantage of the fact the Ag+ adsorption introduces significant spectral change in the AuNP surface plasmonic resonance, we probed the kinetics of the Ag+ adsorption using the time-resolved UV-vis spectroscopic analysis. The structure and properties of the Ag+-treated AuNPs were also studied with surface enhanced Raman spectroscopy (SERS) by using butanethiol (BuT), a monothiol, and 1,4-benzenedimethanethiol (BDMT), a dithiol as the model probes, which provides rich information regarding the mobility of the surface silver and the SERS activity of the Ag+-stained AuNPs.Herein we provide further supporting evidence that AgAll the chemicals were purchased from Sigma-Aldrich and used as received. Nanopure water (18 MΩ-cm) (Thermo Scientific) is used throughout all experiments. UV-vis spectra were acquired with an Olis HP 8452 diode array spectrophotometer. Polarized resonance synchronous spectra (PRS2) were acquired using the Fluoromax-4 spectrofluorometer equipped with an excitation and detection polarizer. PerkinElmer ELAN DRC II inductively coupled plasma-mass spectrometer (ICP-MS) was used for the silver quantification. Litesizer 500 (Anton-Paar) instrument was used for the zeta potential measurements. A Thermo Scientific K-Alpha X-ray photoelectron spectrometer system was used for the XPS measurements. A LabRam HR800 confocal Raman microscope was used for Raman and SERS acquisitions with 632 nm laser excitation. Reflective sample substrate (RSS) slides from Raminescent, LLC were used for all SERS acquisitions. These RSS slides are highly reflective with negligible fluorescence and Raman background  AuNP were synthesized in-house using the citrate reduction method Frens, . The ~303 to the dialyzed AuNPs and mixed using a vortex mixer. The mixture was left to sit overnight at ambient conditions before further usage. The kinetics of the Ag+ binding to AuNP was conducted with the time-resolved UV-measurements for the sample prepared by mixing the dialysis-purified 13 nm AuNPs.All the as-synthesized AuNPs were dialyzed four times with Nanopure water using standard regenerated-cellulose membrane (MWCO is 12–14 kD) purchased from Spectrum Labs. The as-received dialysis membranes were washed thoroughly before use. The silver staining was conducted by adding known amount of AgNOPRS2 is a new spectroscopic method that enables quantitative decomposition of the sample UV-vis extinction spectrum into its absorption extinction and scattering extinction spectrum. The theoretical background, spectral acquisition, and data analysis procedure are available in recent publications . Each zeta potential is an average of 500 scans. The sample solution was equilibrated in the cuvette for 2 min prior to each acquisition.Dialyzed AuNPs were mixed with AgNOAll the SERS spectra were acquired using Olympus 10 × objective (NA = 0.25). The He/Ne laser with an excitation wavelength of 632 nm was used and the laser power before the objective was 1.3 mW for the SERS acquisition. The spectrograph grating was 600 grooves/mm. The acquisition times for SERS spectra were varied between 10 and 200 s. The Raman shift was calibrated with a neon lamp.+ adsorbed was quantified using similar procedure described previously . A known volume of the supernatant was digested with aqua-regia to quantify the free Ag+ ions in the solution. All the digested samples were diluted with 18 MΩ-cm Nanopure water.The amount of Ag+ can react with the excess reagents, complicating the study of the Ag+ binding to AuNPs. While the dialysis is effective in removal of the free small molecules in solutions  s.The fact that the Agurements . The worments  with increasing Ag+ concentration before it reaches a plateau value of 3 mV when the nominal Ag+ concentration is 150 μM T, and gauche υ(C-S)G conformers are at ~680 and ~610 cm−1, respectively and C-C stretching peaks for trans υ(C-C)T, and gauche υ(C-C)G are ~1,070 and ~1,020 cm−1, respectively (Rycenga et al., +-stained AuNPs are mostly in highly ordered trans conformers, but totally disordered on the AuNPs without Ag+ staining.The structure and conformation of alkanethiols on AuNPs are deduced from its skeletal C-S and C-C stretching frequencies. The C-S stretching peaks for the trans conformer on the AgNPs, but totally disordered on the AuNPs (Ansar et al., +-stained AuNP indicates that the Ag-BuT complex formed on the Ag+-stained AuNPs are also mobile.Earlier research showed that BuT is in a highly ordered + on the Ag+-stained AuNPs comes from the SERS spectra obtained with dithiol BDMT. There is a relatively strong S-H peak in the 2,600 cm−1 region in the SERS spectrum obtained with the BDMT on AuNPs, indicating there are significant intact thiols on the BDMT on AuNPs. Earlier study has shown that the intact S-H appears only when BDMT is at upright positions when BDMT approaches full monolayer adsorption on the AuNP surfaces (Gadogbe et al., +-stained AuNPs indicates that the adsorbed Ag+ on the dialyzed AuNP can reach the distal thiol that otherwise unreactive to the AuNPs.Further evidence of the mobility of the surface adsorbed Ag+ binding to AuNPs using a series of in-situ techniques including the AuNP surface plasmonic resonance, zeta-potential titration, pH measurements, and SERS acquisitions. All the experimental data indicate that the Ag+ adsorbs onto AuNPs as cationic silver species, but not as the zero-charged silver atoms. Mechanistically, the Ag+ adsorption is mediated by the surface adsorbates remaining on the surface of the dialyzed AuNPs, and it proceeds through a fast charge neutralization reaction in combination with a relatively slow proton generation reaction. This work is important not only for its new insights into the Ag+ binding to AuNPs, but also for the experimental strategies that should be useful for probing a wide range of nanoparticle interfacial interactions.In conclusion, we have conducted a systematic study of the AgSA, XL, and JX all helped with experiment design, performed experiments, analyzed data, plotted graphs, and prepared manuscript. YP conducted Zeta potential measurement. NF supervised the Zeta potential measurement and responsible for part of the writing. DZ designed and supervised the experiments and was responsible for writing 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.