The current scenario of the COVID-19 pandemic is significantly different from that of the first, emergency phase. Several countries in the world are experiencing a second, or even a third, wave of contagion, while awaiting the effects of mass vaccination campaigns. The aim of this report was to provide an update of previously released recommendations on prioritization and restructuring of urological activities.A large group of Italian urologists directly involved in the reorganization of their urological wards during the first and second phase of the pandemic agreed on a set of updated recommendations for current urology practice.The updated recommendations included strategies for the prioritization of both surgical and outpatient activities, implementation of perioperative pathways for patients scheduled for elective surgery, management of urological conditions in infected patients. Future scenarios with possible implementation of telehealth and reshaping of clinical practice following the effects of vaccination are also discussed.The present update may be a valid tool to be used in the clinical practice, may provide useful recommendations for national and international urological societies, and may be a cornerstone for further discussion on the topic, also considering further evolution of the pandemic after the recently initiated mass vaccination campaigns. Starting from February 2020, the coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has generated a rapid and tragic health emergency worldwide due to the need to assist an overwhelming number of infected patients with severe acute respiratory syndrome requiring mechanical ventilation in intensive care units. Simultaneously to aggressive containment efforts implemented by the national political and health authorities, suspension of all outpatient and non-urgent activities coupled with restrictions in scheduling non-deferrable and urgent interventions has determined a major reorganization of all surgical activities, mainly depending on the availability of anesthesiologists, mechanical ventilators, and hospital beds. This together with other expert-opinion documents that have classified urologic procedures in deferrable, semi-deferrable, non-deferrable, and urgent according to disease prognosis, have been widely cited in the peer-reviewed literature, and also considered in the drafting of several national and international guidelines published during the emergency phase of the pandemic.14In this war scenario, in March 2020 a large team of Italian experts affiliated to the Research Urology Network drafted a document with the purpose to provide a framework to reorganize urological activities, and to identify the procedures to prioritize in the management of the most common urological conditions during the emergency phase of the COVID-19 pandemic.The end of the first lockdown, which took place in May 2020 in most European countries, marked the end of the emergency phase and the start of second phase of the pandemic, characterized by a decrease in contagion index across most countries. Urological activities gradually returned to an acceptable status in all geographic areas. Several political and economic interventions were planned to increase the human and technical resources needed to sustain a possible second wave of contagion, which indeed started from October 2020. For this reason, new restrictive measures were implemented in most European countries, which ultimately reduced the impact of the second wave on health systems of most countries, and, consequently, on the urologic activities in most COVID-19 hospitals. Obviously, the heterogeneous patterns of virus diffusion across different countries may be responsible for a variable impact on the urological activities.6 we believe that the urological community needs an update of previous recommendations on priority and reorganization of urologic activities. The present document is based on the opinion and experience maturated by the panel members in the management of urological conditions during the first and second phase of the pandemic. The panel scheduled to update their previous document at the end of December 2020. The final version of the present document was approved unanimously on January 10, 2021.Considering that the current scenario is significantly different from that of the first phase, and predicting a possible third wave while awaiting the implementation of mass vaccination campaigns,The panel suggests that all possible patient-related factors and comorbidities should be taken into account when triaging urgent conditions and planning corresponding treatments.According to the current situation and the experience matured out of the emergency phase of the pandemic, the panel strongly disagrees on the opportunity to replace some surgical treatments for urological malignancies with other treatments that do not require anesthesia. Alternative treatments to surgery should be taken into consideration in the decision-making process according to international guidelines and independently from the COVID-19 pandemic. Therefore, the opinion of the panel is that all efforts should be made during the second and third phase of the pandemic to deliver appropriate treatments in order not to jeopardize cancer-related outcomes and quality of life. urologic procedures for cancers have been classified in urgent (<24 h), non-deferrable (4–6 weeks), semi-deferrable (6–12 weeks) and deferrable (>12 weeks). All procedures for which a delay can be detrimental to oncological outcomes should be considered non-deferrable. Similarly to the recommendations of the European Association of Urology Guidelines Office Rapid Reaction Group (EAU GORRG), Radical cystectomy should be still considered the gold standard treatment of muscle-invasive bladder cancer, ad regarded as a non-deferrable procedure. Moreover, we strongly support the option to treat patients, too, with high-risk non-muscle invasive bladder cancer that are unresponsive to intravesical Bacillus Calmette-Guerin (BCG), within 4–6 weeks.Concerning bladder cancer, we advocate to urgently (<24 h) proceed to transurethral resection or palliative cystectomy in the presence of intractable hematuria due to bladder cancer rather than to immediate radiotherapy ± chemotherapy as previously recommended by the EAU GORRG.As for kidney cancer, while surgical treatment for cT2-4 renal masses should be still considered as non-deferrable, management of cT1a and cT1b renal masses can be postponed to more than 12 weeks and 6–12 weeks, respectively. Although international guidelines support the use of active surveillance and ablative percutaneous treatment as an alternative to surgery in the treatment of selected patients with cT1a parenchymal renal tumors, we think that in this phase the final decision should not be influenced by the COVID-19 pandemic.As for prostate cancer, the panel still considers radical prostatectomy with pelvic lymph-node dissection as non-deferrable in high-risk patients with localized disease or in those with locally advanced disease who are not suitable for, or refuse, radiation therapy ± androgen deprivation therapy. Radical prostatectomy ± pelvic lymph-node dissection can be considered as a semi-deferrable or deferrable procedure in patients with intermediate- or low-risk disease.The Authors still suggest that when planning surgical procedures that are considered non-deferrable from the oncological standpoint, other considerations should be made, mainly with regard to the availability of intensive care for possible postoperative assistance. Centralization of more complex surgical procedures to high-volume centers is a strongly recommended measure to minimize the need for postoperative intensive care in the second and third phase of the pandemic. Currently, some months after the end of the emergency phase, many patients with benign urological conditions are still waiting for surgical treatment. In the previous document, all the procedures to treat benign diseases were considered deferrable until the end of the emergency phase. Moreover, the appropriate endourological treatment for non-complicated obstructing ureteral or renal stones should not be postponed, rather performed within 4–6 weeks.The panel agrees with the option to offer immediate treatment in all cases of complicated obstructing ureteral or renal stones .Surgical treatment of patients with LUTS/BPH unresponsive to medical therapies should be considered semi-deferrable in case of complications  or indwelling transurethral catheter or suprapubic tube. Surgical treatment of patients with non-complicated LUTS/BPH can be considered deferrable according to the center waiting list.The panel recommends that patients waiting for deferrable procedures should be periodically monitored with the appropriate exams in order to detect a possible clinical worsening. In that case, the procedure should be upgraded to semi-deferrable or non-deferrable. Strengthened by the efficacy of individual protection measures  and the newly launched vaccination campaign, it is our view that all outpatient procedures can be regularly performed without substantial limitations, except for a mild reduction in the number of daily cases. Outpatient procedures include prostate biopsy, flexible cystoscopy, replacement of ureteral stent or nephrostomy tube as well as all diagnostic procedures for benign conditions (e.g. pressure-flow study). Also, intravesical therapies  for the treatment of high- or intermediate-risk non-muscle-invasive bladder cancer should be regularly performed.The current panel position about outpatient procedures differs substantially from the previous one during the emergency phase. reported the presence of in the urine of 6.9% of the convalescent patients, in most other studies no single case of viral shedding in urine was documented. However, all health care workers should follow national and hospital rules in order to decrease the risk of contagion. Urgent surgical procedures on SARS-CoV-2 positive patients should be performed in dedicated operating rooms in adherence to clinical pathways implemented by the single hospitals. Considering the urgent procedures indicated in Urologists practicing in hospitals treating COVID-19 patients may be in need to perform urgent procedures or consultation on infected patients. Although Ling et al.The increasing number of patients who are testing SARS-CoV-2 positive has opened a discussion about the optimal pathway for elective surgical treatment of urological malignancies or complicated benign conditions in infected, asymptomatic patients. The panel agrees that these patients should be appropriately scheduled and treated as soon as possible after test negativization.The panel agrees that in the current pandemic phase, the use of standardized surgical techniques in order to reduce the operating room time and the risk of postoperative complications is no longer recommended, but only suggested. Moreover, the panel recommends that all procedures should be performed by experienced surgeons or under their tutorship in the context of modular training programs. Implementation of new technologies as well as specific clinical studies on new technologies should be carefully considered, and applied only after local ethical committee approval. guidelines from EAU Robotic Urology Section provided a list of non-deferrable or semi-deferrable robot-assisted procedures to be performed based on the different impact of the COVID-19 pandemic across countries and hospitals. According to a systematic review of literature by the panel, it was concluded that specific clinical studies are needed to investigate the effective presence of the virus in the surgical smoke of different surgical procedures, and its concentration, and that, meanwhile, the adoption of all the required protective measures is mandatory. Moreover, we still suggest the implementation of the set of the intraoperative measures proposed by Zheng et al. , as reported in the previous recommendation.At the beginning of the COVID-19 pandemic contrasting opinions have emerged about safety in the utilization of laparoscopy procedures  as a consequence of the potential risk of dissemination of SARS-CoV-2 via laparoscopy gas. Whereas the Intercollegiate General Surgery Guidance recommended that laparoscopy should not be used, the panel recommends the implementation of a multidisciplinary team of surgeons, anesthesiologists and operating room personnel who assign the most appropriate priority to patients, taking into account the availability of all resources necessary to activate the operating rooms. A pool of surgical procedures to be prioritized should be identified with proper planning on a weekly basis, and the possibility to accomplish them should be verified daily.In agreement with previous indications,According to currently adopted protective measures, all patients scheduled for prioritized surgical procedures should be preoperatively tested for SARS-CoV-2 with a nasopharyngeal swab. The same should apply to patients requiring an urgent procedure, if the procedure can be deferred until the test result is available. The accuracy of rapid nasopharyngeal tests remains questionable. Nevertheless, it is always recommended that all patients had their temperature measured immediately before hospitalization, in order to prevent the hospitalization of suspected cases directly in the urological wards. At the time of hospitalization, all patients should wear a mask. Moreover, all urological departments in which logistics are suboptimal (i.e. one-bed rooms or larger two-bed rooms) should reduce the number of beds in order to increase the distance among patients.The panel suggests considering the opportunity to screen patients for SARS-CoV-2 immediately before discharge, too.Finally, as far as the complex management of patients with genitourinary malignancies is regarded, the implementation of virtual multidisciplinary meetings based on locally available web technologies is still recommended.15 preoperative examinations in patients scheduled for elective surgery should be performed with a single hospital access whenever possible, after a negative telephone triage for COVID-19 symptoms, and using preferential and well-defined hospital pathways. Routine exams to define the anesthesiological risk and a nasopharyngeal swab for SARS-CoV-2 should always be performed before surgery, whereby it is advisable to guarantee a single access point to facilitate screening procedures in accordance with the indications of the Center for Disease Control and Prevention. After ruling symptoms and signs of COVID-19 out, hospitalized patients should wear a surgical mask and observe the hygiene rules recommended for the general population. The recommendation to use individual protection systems is mandatory both for patients and for healthcare workers.In agreement with our previous recommendations,Although patients following urologic surgical procedures should be discharged when their clinical conditions and logistics allow for a safe return home, the panel encourages an early discharge so as to reduce the potential risk of nosocomial infections (including COVID-19) and increase the bed availability for other patients. Anyway, patients discharged with indwelling drains or urinary catheters should be trained for completely autonomous home care. With regard to this, photo or video tutorials could be of aid for patients and their relatives to ease home care of urinary stoma. Patients discharged with indwelling internal ureteral stents need no specific advice. Moreover, using absorbable material for skin suture avoids subsequent hospital visits for their removal. We believe it is useful that ward staff provide as many instructions as possible during the hospital stay in order to facilitate home care. Telemedicine could be implemented to monitor those patients with a proper frequency during the early postoperative course according to their clinical needs.Informing patients on the results of a pathology examination, especially after procedures for known or suspected genitourinary malignancies, has been one of the most critical points in the clinical pathway during the early phase of the pandemic. Contrary to the emergency phase, we now recommend that the pathology report should be discussed in the context of a scheduled face-to-face follow-up visit, in view of the current medico-legal restrictions and privacy-related issues. reported a quite successful use of telehealth in selected settings of patients with prostate cancer, urinary incontinence, pelvic organ prolapse, non-complicated urinary stones, and urinary tract infections in non-pandemic times. It was, however, concluded that more studies are needed, especially to test the role of telehealth on other highly prevalent urological malignant and benign conditions. Considering that more robust data on long-term efficacy, safety, and health economics of telemedicine are mandatory, the panel suggests that at least the adoption of popular tools such as laptops, tablets, smartphones, or emails should be recommended for telemonitoring. Urology wards should implement systems for priority communications via telephone or email from patients to the medical or nurse staff in order to check the clinical course and decrease the risk of inappropriate hospital visits.There are two main areas of development for future scenarios. First, the reorganization of outpatient and inpatient urological activities determined by the current pandemic has the potential to favor the implementation of telemedicine. In a recent systematic review of the literature, Novara et al.6 This will surely represent an immediate advantage in decreasing the risk of contagion among health workers with a positive impact on all medical activities, especially those performed in COVID-19 areas. Moreover, vaccination could mark the restart of didactic activities, such as training, courses, laboratory activities, and others. Finally, the possibility to track vaccinated patients could allow to progressively increase the currently held back urological activities, hence decreasing waiting lists. Although mass vaccination is a big step forward in the battle against COVID-19, it is still premature to predict over which time horizon, the anticipated effect of decreasing contagion and/or disease severity will be achieved. Therefore, the impact of vaccination on the reorganization of outpatient and inpatient urological activities might not be evident before 8–12 months from the start of the vaccination campaign. At the end of the vaccination phase, a further adaptation of the currently updated recommendations will be needed. Specifically, criteria to reschedule the surgical procedures that have been suspended in the past and current phases of the pandemic as well as resources to accomplish this challenging objective should be defined.Second, we have just entered the era of vaccination against SARS-CoV-2, with the approval of vaccines that have been shown to be effective in pivotal phase III clinical trials by health authorities in many countries of the world.The present white paper is the first update of a previous document published in the emergency phase of the COVID-19 pandemic, and is based on the opinions and experience of a group of urologists directly involved in the organization of some urological wards in Italy. An adaptation of the recommendations provided in the emergency phase is needed because numerous changes have characterized the urology practice in the last months, and several countries in the world are experiencing a second or even a third wave of contagion. The present update will hopefully be a valid tool to be used in the clinical practice and, possibly, a cornerstone for further discussion on the topic, also considering further evolution of the pandemic after the recently initiated mass vaccination campaign.


The present study concerns the phenomenon of the co-dependence of value orientations and consumer behaviours. Although the idea of the overall connections between both areas is not new, the article contributes to the knowledge about relations between very specific consumer behaviours and social value orientations among people married or in an informal partnership. Using the obtained data, we examine to what extent the prosocial, reciprocal, and egoistic value orientations coexist with compensative, compulsive, and demonstrative buying. The analysis confirms the hypotheses that representatives of the reciprocal and egoistic orientations show susceptibility to compensative and compulsive buying to a greater extent than persons preferring other value orientations. In addition, the data show co-dependence of the reciprocal value orientation and demonstrative buying, while the prosocial value orientation seems to protect against compulsive buying. According to the regression analysis, this effect disappears if prosocially oriented persons suffer from low self-esteem at the same time being characterised by strong materialism. All hypothesised relations between value orientations and consumer behaviours have been analysed in multidimensional models considering materialism, self-esteem, age, and gender as the main factors of compensative and compulsive buying. The findings come from the 2017 survey based on a statistically representative sample of 1,121 adult Poles who were then married or in an informal partnership. The German Compulsive Buying Indicator and Lange’s Scale of Demonstrative Buying were introduced to measure consumer behaviours. Sociologists have discussed the links between value orientations and consumer behaviours for a long time. Already Weber  pointed In a certain sense, the above outlined relation is reflected in the contemporary consumer society. Although the transcendental goal of mundane life in this type of society disappeared, the social role of consumer behaviours is still the same. The Protestants described by Weber used consumer goods as symbols of God’s favour, which guaranteed them the social prestige. Contemporary consumers use goods as socially desired symbols of meaning, satisfaction and self-actualization in consumer society  which prIndependently of the overall relations between values and consumption integrated e.g. in practised lifestyles , 6, reseBased on the literature review, we believe that overall dispositions to assess and to act in interdependent situations  are related to specific types of consumer behaviours. In this paper, we focus on compulsive, compensative, and demonstrative buying. So far, this relation has not been examined within empirical projects conducted on countrywide samples. Hence, this study will contribute to the existing literature on the new aspect of the relationship between social value orientations and consumer behaviours.A broader discussion about disorders connected with buying began at the end of the 1980s triggered by the study conducted by Faber, O’Guinn and Krych . Since tWe expect relatively strong bonds between value orientations and compulsive, compensative, and demonstrative buying for several reasons. One of them is sociologists’ observation concerning the development of consumer society promoting consumerist lifestyle and life strategies . During To what extent consumers take advantage of the above functions of cultural values inherent in material goods depends more or less on value orientations. The connections between value orientations and consumer behaviours are unavoidable because people’s judgments in one area are more or less coupled to judgments in other areas, and value orientations as a specific socio-cultural “baggage” characterising the social environment, social group or an entire society can spill over into other areas of life including consumer behaviours .The remaining part of this paper is organised as follows: at the beginning, we deal with the theoretical framework and define the types of value orientations and consumer behaviours which we are interested in. Then, we describe what we expect putting four hypotheses and seeking justification for them. In the next section, we present the methodological basics of our empirical study and the data used to verify the hypotheses. Finally, we conclude in a critical discussion about the potential reasons for the observed relations between value orientations and consumer behaviours. Remarks about the limitations of the study end our paper.The concept of social value orientations explains people’s disposition to assess and to act in interdependent situations. This disposition differs individually depending on a person’s preference concerning what kind of relation between their own and other people’s good they are ready to accept. These individual preferences can be assigned to more or less coherent types placed on the axis of two extremes: prosocial and individualistic value orientations . ProsociPersons oriented individualistically prefer the maximization of their own outcomes with little or no respect for others’ outcomes. Individualists are characterised by focus on their own individual sphere, putting their own good above other people’s good, indifference towards the interests of other people, and insensitivity to social issues. In the literature, individualists are often combined with the segment of so-called competitors in a common type of proselfs. Mainly, competitors are interested in maximization of the relative difference between their own outcome and the outcome of others , 17. BecAccording to Peter Blau’s social exchange theory , individBased on the social exchange theory, prosocials might be split into two segments: prosocials in the narrow sense and reciprocals . Representatives of the first group act really altruistically accepting potential inequality of profits in somebody’s favour. Reciprocals try to minimize the differences of the exchange partners’ outcomes caring for the balance between their own good and other people’s good. On the one hand, they are capable of acting prosocially but only being convinced that the exchange partner will be able to return the favour in the future and “the value” of the repayment will be the same. On the other hand, reciprocals are able to accept a prosocial act directed to them if they positively assess their future ability to repay the act by doing something of comparable importance for the exchange partner. The orientation reflects a specific defence mechanism which makes people maintain good relationships just in case of crisis situations and the necessity of receiving other people’s help. The main motif of reciprocal social actions including help directed to people in need is the expectation that the actions will be repaid in the future, although the reasons for the repayment can be quite different .The reciprocal exchange resembles the most an economic exchange when partners know exactly the potential profits beforehand if the exchange should come through (e.g. a purchase of a car). Similarly, reciprocals expect that a favour should be returned by an exchange partner at the first opportunity and the returned favour should be of the same weight. For this reason, reciprocals prefer social exchange conducted directly rather than indirectly. This rule is ignored by prosocials. Although they take part in the social exchange game, they expect neither a direct repayment of their prosocial acts nor a repayment valued on the same level. In addition, they count on the possibility that their prosocial act will not be repaid at all directly or even they want to avoid a direct repayment.In what way might the nature of the egoistic value orientation be explained compared with the prosocial and reciprocal variants? At first sight, the egoists’ social exchange seems to be a reverse of the prosocials’ approach. But this statement needs an additional explanation. Egoists shape the social exchange in such a way that their profit which ends the exchange process should be greater than the profit of the exchange partner. They achieve this goal in two ways. Firstly, they break the basic reciprocal principle: the receiver of an act bringing them profits should repay it on the same level in the near or further future. Secondly, even though egoists initiate the social exchange, they do it to provoke a reciprocal act of their exchange partners which finally is not repaid or repaid but on an insufficient level. The social exchange preferred by egoists resembles economic activities on the free market based on the rational choice principle maximizing the profits and minimizing the incurred costs at the same time .According to Antonides and van Raaij , the terConsumer behaviours compose the domains which are “sets of behaviours frequently organized around a common goal” , p. 178.Although the phenomenon of compulsive buying was noticed by Kraepelin  at the bCompulsive buying can be understood as a behavioural addiction in three basic ways: as an impulse control disorder, an obsessive-compulsive disorder or a neuroadaptive process. In the first case, the compulsive buyer loses control over impulses on account of an increasing tension or anxiety which can be replaced by the experience of pleasure, satisfaction or relax only due to buying. Treating compulsive buying as an obsessive-compulsive disorder means that a compulsive buyer experiences an internal pressure to buy, which reduces unpleasant psychical states. From the neuroadaptive point of view, compulsive buying is experienced by the brain as a reward. An excessive repetition of the rewarding purchase leads to the formation of the neuroadaptive mechanism analogous to the development of substance abuse . The undFrom the point of view of the Rational Choice Theory, compulsive buying can be found to be a type of an irrational consumer behaviour as opposed to compensative, demonstrative, and rational buying. Although the post-modern paradigm inclines towards the conclusion that each consumer constructs their own rationality, the application of the principle of maximizing the expected utility might be helpful to fix the clear borderlines between compulsive buying on the one hand and compensative, demonstrative, and rational buying, on the other. In general, consumers choose this behaviour from a set of the accessible options, which maximizes the profits or minimalizes the incurred costs . Hence, Although the borderline between compulsive and compensative buying is fixed by the balance between the profits and the costs, sometimes both buying styles overlap. Assuming that compulsive buying is a kind of behavioural addiction, the compensation experienced during purchase constitutes the object of the addiction. In this sense, compulsive buyers always purchase compensatively at the same time. In contrast, compensative buying might be an autonomous purchase style which may precede the stage of compulsive buying but it does not have to lead to it . This idThe roots of demonstrative buying are in the need of social prestige. Demonstrative buyers, like compensative buyers purchase the given items to use their attributes to achieve goals quite different from the utility functions of the items. In case of demonstrative buying, improvement of one’s own social status and self-esteem is the primary benefit. Hence, demonstrative buyers buy those goods which are perceived socially as fashionable, exclusive and desired. For this reason, brands play a special role for them, which in fact is taken advantage of by marketers very willingly. Like in case of compensative buying, the desire for demonstrative purchase can turn into compulsive buying if the balance between costs and profits is upset and the psychical, social, and economic costs exceed the profits in the form of an improved social status.The goal of the study was an attempt to answer the question if correlations between the above defined types of value orientations and consumer behaviours exist. The following hypotheses will be tested:H1: The stronger the prosocial value orientation, the stronger susceptibility to compensative buyingH2: The stronger the reciprocal value orientation, the stronger susceptibility to compensative/ compulsive buyingH3: The stronger the egoistic value orientation, the stronger susceptibility to compensative/ compulsive buyingH4: The stronger the reciprocal value orientation, the stronger susceptibility to demonstrative buying.A further analysis intends to verify whether the correlations between value orientations and consumer behaviours appear or disappear if the variables describing the main factors of compulsive buying such as materialism, self-esteem, age and gender are included into the multidimensional model.The assumed hypotheses have their roots in the theoretical concept of the social value orientation and social exchange. Prosocials take into consideration the interest of other people if a conflict occurs between their own interest and other people’s interest. Prosocials are altruistically oriented, which means their acceptance of inequality in the process of the social exchange. Some researchers indicate that purely altruistic motifs of prosocial behaviour do not exist. More or less, egoistic components are hidden in altruistic behaviours; it might be an appreciation of the social environment or an increasing level of the brain neurotransmitters responsible for the pleasure feelings. The deficiency of the expected co-results of the altruistic behaviours might lead to decreasing self-esteem, sometimes resulting in different behavioural addictions , 33. CerAs mentioned, reciprocals expect that their prosocial activity will be repaid by the exchange partner on the same level in the near or further future. The better social position of reciprocals is, the bigger future reciprocated benefits might be expected. Repaid benefits should be proportional not only to the primary prosocial act, but to the social position of reciprocals. For this reason, reciprocals can try to improve their social position to have more benefits in the future if they decide to act prosocially. In consumer society, a demonstrative consumer behaviour is a relatively easy way to improve the social position thanks to the purchase of goods perceived as socially desired such as brands. People reciprocating the received profits have hopes for the future winnings in the reciprocal cycle. In more complex social structures, social norms replace the direct exchange between individuals. Then, the conformity referring to the social expectations included in the social norms provide social acclaim for an individual. Because consumer society is permeated with consumerism, demonstrative buying and consumption are the best way to gain the social prestige true to the social expectations. Although demonstrative buying and consumption do not lead to a direct social exchange with other members of consumer society, reciprocals gain good reputation which might be profitable in the future social exchange. Like the wealthy persons who donate for charity to gain social reputation among the representatives of their social class and not to win profits from poor people directly, reciprocals buy demonstratively to strengthen their social position, which can be paid off in the future .We expect a co-dependence of the reciprocal value orientation and demonstrative buying as well as compensative/ compulsive buying. On the one hand, a reciprocal act of a debtor might not occur. If a person expecting the act is oriented reciprocally, they might seek compensation rooted in compensative buying. On the other hand, especially in a consumer society, demonstrative buying, aiming to improve the social position for future reciprocal acts, can become compulsive. Over-average usage of the symbolic values of consumer goods to gain social prestige and to improve social positioning can lead to susceptibility to demonstrative buying which is difficult to hold back. If the costs of the acts began to exceed the profits, it means that demonstrative buying turns into compulsive buying.Egoists represent quite a different social orientation than prosocials. As mentioned, egoists are characterised by focus on their own interest without consideration of other people’s interest . In addiThe survey about compulsive buying was conducted in Poland in 2017 on the statistically representative sample of 1,121 adult Poles married or in an informal partnership . Once thThe procedure of the data collection was structured as follows. The invitation to the survey was sent to all members of the GfK research panel who met the recruitment criteria . The completed questionnaires were collected until the assumed quotas in terms of gender, age, size of the locality, and region of residence were filled. The quotas based on the results of a previously conducted countrywide survey on the randomly selected sample of 1,000 Poles aged 18 years and more (face-to-face interviews at respondents’ home).The following table presents the sociodemographic structure of the sample.The factor analysis based on thirteen statements describing different behaviours and principles relating to value orientations indicated four coherent components .Three components might be described as:prosocial value orientation characterised by more or less frequent activities: 1) regular coming to sick unrelated persons’ aid; 2) selfless neighbourly help; 3) coming to disabled or older persons’ aid on the streets or in buildings; 4) coming to friends’ aid in case of e.g. redecoration or removal; 5) coming to unknown persons’ aid in case of e.g. showing the wayreciprocal value orientation characterised by the agreement with the following statements: 1) I get involved in coming to other persons’ aid if I can have benefits connected with it; 2) I find that we should not help somebody who is not capable of repaying for the help; 3) It is not worth devoting time, e.g. a hobby if it is not connected with financial benefitsegoistic value orientation characterised by the disagreement with the following statements: 1) Giving makes me happier than receiving; 2) It happens that I help my friends independently of whether I can have benefits from it; 3) I have my principles and I never change them.The scales exhibit a sufficient extent of the convergent validity. The particular items included in the scales show a high level of the mutual correlation .The scales of prosocial, reciprocal, and egoistic value orientation based on the above factors achieve a satisfying level of reliability .The discriminant validity of the scales was examined based on six addition statements which are connected with the construct of the scales in terms of content. Because the statements were measured on the nominal level, the t-student test for two independent samples was used to check if it is possible to reject H0 hypothesis according to which the mean values on the prosocial, reciprocal, and egoistic scales for the subgroups are equal. The results of the analysis are presented in the following table .The results of the t-student tests makes it possible to reject H0 hypotheses according to which: 1) the mean values on the scale of the prosocial value orientation for persons not oriented prosocially and persons oriented prosocially are equal; 2) the mean values on the scale of the reciprocal value orientation for persons not oriented reciprocally and persons oriented reciprocally are equal; 3) the mean values on the scale of the egoistic value orientation for persons not oriented egoistically and persons oriented egoistically are equal. Hence, the discriminant validity of the built scales can be assumed.On the next step, because of different length, the variables were submitted to the procedure of recoding to 10 point scales. Finally, the standardised scales of value orientations underwent the stepwise regression analysis in the model taking into consideration dependent variables of compulsive and demonstrative buying and independent variables such as materialism, self-esteem, age, and gender.The tendency to compensative and compulsive buying was measured by the German Compulsive Buying Indicator consisting of 16 statements assessed on the four-point scale from 1 (“I don’t agree”) to 4 ; hence, the GCBI amounts to the values between 16 and 64. Following Faber and O’Guinn , 30, resFirst, the one-dimensionality, reliability and normal distribution of the results on the GCBI scale were checked. The scale appeared as one-dimensional . In the factor analysis only one component was extracted and the solution could not be rotated. At the same time, the GCBI scale shows a high degree of internal consistency achieving a very satisfying degree of reliability (Cronbach’s Alpha = 0.94). The coefficients of skewness and kurtosis do not exceed the interval between -1 and +1, thus indicating that the distribution of the GCBI scale is approximately normal .The demonstrative type of consumer behaviour was measured on Lange’s scale  consistiThe statistical traits of the above scales allow the application of the t-student test for two independent samples, ANOVA procedure, as well as the linear stepwise regression analysis. To sum up, the GCBI as well as Lange’s scale seem to be especially useful to measure compensative, compulsive, and demonstrative buying.The mean value on the GCBI scale achieved 31.08 and the standard deviation 9.26. For this reason, those respondents were qualified as compulsive buyers who achieved the result on the GCBI scale at least on the level of 50. In total, 3.9% of such cases were found in the general population. Those respondents who achieved the result of 41–49 were qualified as compensative buyers. 14.8% of such cases in the whole sample were indicated. In general, 18.7% of adult Poles married or in an informal partnership displayed susceptibility to compensative or compulsive buying.The demonstrative type of consumer behaviour is significantly more widely prevalent in the Polish society than compensative and compulsive buying. The results on Lange’s scale aggregated to the 5-points Likert’s scale prove that 5.8% of Poles show a very strong susceptibility to demonstrative buying. In total, 1/3 of Poles buy demonstratively more or less often. According to the expectations, demonstrative buying positively correlates with compensative/ compulsive buying. The coefficient of Pearson’s r = 0.327 (p < 0.001) confirms that the stronger susceptibility to demonstrative buying, the greater probability of compensative/ compulsive buying.The results of the cluster analysis taking into consideration the above described standardised scales show that the biggest segment includes persons representing prosocials. The declarations of almost 2/5 of respondents (38.7%) indicated their belonging to the segment of prosocially oriented persons. About 1/5 of Poles represent the segment of egoists (17.3%). The size of the segment embracing reciprocals is very similar to the last one (16.0%). The remaining part of Poles (28%) represent other types of value orientation.The results of the t-student test for two independent variables confirm the assumptions that in some cases the examined types of consumer behaviours coexist with the value orientations. The average value on the GCBI scale equals 30.3 among prosocials, while representatives of other value orientations amount to 32.7. The differences between the mean values are statistically significant  = 3.973, p < 0.001). The result allows to point out that susceptibility to compulsive buying is weaker among prosocials than among the persons inclined to other value orientations. In case of demonstrative buying, the statistically significant differences on Lange’s scale between prosocials and members of other segments do not exist.The reciprocal value orientation seems to coexist with compulsive and demonstrative buying. The mean value of 36.3 is pointed out for reciprocals, whereas persons inclined to other value orientations obtain the mean of 30.9. A similar relation is observable in case of demonstrative buying. Reciprocals achieve the mean on Lange’s scale equalling 16.2, while the interviewed persons not belonging to the segment are characterised by the mean of 14.5. The above presented differences of the mean value are statistically significant  = -6.602, p < .05; Lange’s scale: t = -5.320, p < 0.001).The egoistic value orientation differentiates susceptibility to compulsive buying, too. While egoists achieve the mean of 34.9, the persons belonging to other segments obtain the result of 31.1 on average. Similarly to the above presented results, the difference is statistically significant  = -5.061; p < 0.001). In case of egoists, the fact of belonging to the segment does not differentiate susceptibility to demonstrative buying statistically significantly.Because the compensative buying scale does not exist independently of the GCBI scale, the relations between value orientations and susceptibility to compensative buying were examined on the basis of crosstabs. It turns out that belonging to the segment of compensative buyers (15.8%) is differentiated by the reciprocal and the egoistic value orientations, although to a limited extend. Almost 1/4 of reciprocals represent the segment of compensative buyers at the same time (23.8%), whereas the share of representatives of other value orientations is clearly lower (14.3%). The difference is statistically significant, which is evidenced by the Chi-Square Test with the Continuity Correction . Taking into consideration the 10-point scale of the reciprocal value orientation, the differentiation is still stronger . Similar tendencies are observable in case of the egoistic value orientation. More than 1/5 of egoists belong to the segment of compensative buyers (22.2%), while the share of these buyers among representatives of other value orientations amounts to 14.5%. Again, the difference is statistically significant, which is proved by the Chi-Square Test . Hence, the conclusion can be drawn that representativeness of the reciprocal or the egoistic value orientations coexists with susceptibility to compensative buying to a greater or lesser extent.Finally, the relations between compulsive as well as demonstrative buying and the value orientations were examined based on the linear stepwise regression analysis . The preThe results show that materialism and self-esteem are the key variables which explain the appearance of compulsive buying to the greatest extent. If the prosocial value orientation is included in the model, the effect of materialism and self-esteem on the GCBI scale is the same as at step 4. A growth of susceptibility to compulsive buying by 0.254 (+/- 0.017) on the GCBI scale can be assumed along with an increase of materialism by 1 point, while an increase of self-esteem by 1 point means a loss of 0.552 points on the GCBI scale (+/- 0.050). The effect of age and gender on the GCBI scale is weak, but statistically significant. If age increases by 1 year, the result on the GCBI scale decreases by 0.046 (+/- 0.019), while if a person is a woman the result on the GCBI scale should increase by 2.192 (+/- 0.515). Finally, comparing the t-coefficient, the effect of the prosocial value orientation on the GCBI scale seems to be comparable with the effect of age. A growth of susceptibility to compulsive buying by 0.283 (+/- 0.132) on the GCBI scale can be assumed along with an increase of importance of the prosocial value orientation by 1 point. Although the bivariate analysis of the GCBI scale and the prosocial value orientation confirms the previous assumptions, the regression analysis shows some limitations. Indeed, susceptibility to compulsive buying is weaker in prosocials than in the persons preferring other value orientations. But this effect disappears if prosocials are strongly materialistically oriented and suffer from low self-esteem. In general, even though younger women with negative self-esteem who prefer materialism represent the prosocial value orientation, they will be characterised by a stronger susceptibility to compulsive buying than men representing the opposite features.If the reciprocal value orientation is included in the model, the effect of materialism and self-esteem on the GCBI scale is lesser but still dominant. A growth of susceptibility to compulsive buying by 0.231 (+/- 0.018) on the GCBI scale can be assumed along with an increase of materialism by 1 point, while an increase of self-esteem by 1 point means a loss of 0.494 points on the GCBI scale (+/- 0.050). When the reciprocal value orientation is added, the effect of age becomes statistically insignificant while if the person is a woman the result on the GCBI scale should increase by 2.442 (+/- 0.511). Comparing t-coefficients, the effect of gender on the GCBI scale seems to be comparable with the effect of the reciprocal value orientation. In general, the growth of susceptibility to compulsive buying by 0.751 (+/- 0.170) on the GCBI scale can be assumed along with an increase of importance of the reciprocal value orientation by 1 point. The direction of the observed correlation is coherent with the previously obtained bivariate correlation. Taking into consideration all significant variables, it might be concluded that female reciprocals with negative self-esteem and a preference for materialism at the same time are characterised by a stronger susceptibility to compulsive buying than male reciprocals with healthy self-esteem who reject materialism.The role of the egoistic value orientation in the explanation of compulsive buying is limited, although statistically significant. If the importance of the egoistic value orientation grows by 1 point, an increase of susceptibility to compulsive buying by 0.307 (+/- 0.141) can be expected. If the egoistic value orientation is included into the model, it does not cause changes of the effect of the remaining variables on the GCBI scale. Still, compulsive buying is explained by materialism and self-esteem mainly. The effect of age in this area is very weak, but statistically significant. Again, the direction of the observed correlation is coherent with the previously obtained bivariate correlation. In general, younger female egoists with negative self-esteem who prefer materialism are characterised by a stronger susceptibility to compulsive buying than older men representing the same value orientation, but characterised by healthy self-esteem and a lesser importance attached to materialism.In case of demonstrative buying, the primary role of materialism in the regression models is maintained . IndepenThe role of value orientations in the explanation of demonstrative buying is relatively limited. The prosocial value orientation seems to be the strongest predictor of demonstrative buying among all the analysed value orientations. The growth of susceptibility to demonstrative buying by 0.254 (+/- 0.061) on Lange’s scale can be assumed together with an increase of importance of the prosocial value orientation by 1 point. Self-esteem and age do not play any significant role in this model. Interesting conclusions can be drawn comparing the results with the previously presented bivariate analysis. According to the latter one, hypothesis “zero” assuming no statistically significant differences between prosocials and representatives of other value orientations has been confirmed. The regression analysis finds out that the correlation appears if a prosocially oriented person is a man preferring materialism.The direction of the effect triggered by the reciprocal value orientation is similar, although the power of the effect is weaker. Susceptibility to demonstrative buying is growing by 0.194 (+/- 0.080) on Lange’s scale along with an increase of importance of the reciprocal value orientation by 1 point. Again, age does not play any significant role in the model. In contrast, self-esteem seems to intensify susceptibility to demonstrative buying to a similar extent as the reciprocal value orientation. In this case, the direction of the observed correlation is coherent with the previously obtained bivariate analysis. In general, male reciprocals with positive self-esteem and preferring materialism to a greater or lesser extent are characterised by a greater susceptibility to demonstrative buying than women characterised by the opposite features.The effect of the egoistic value orientation on demonstrative buying is quite opposite in comparison with other value orientations. The previously conducted bivariate analysis does not evidence any statistically significant differences between susceptibility to demonstrative buying of people oriented egoistically and preferring other value orientations. The multidimensional regression analysis shows quite a different picture. A correlation between the egoistic value orientation and demonstrative buying appears if materialism is preferred by men. Then, the probability of demonstrative buying becomes weaker by 0.196 (+/- 0.066) if the importance of the egoistic value orientation grows by 1 point. Similarly to the model including the prosocial value orientation, self-esteem and age do not play any role in the explanation of susceptibility to demonstrative buying.In accordance with our expectations, we observe the phenomenon that some value orientations coexist with some chosen types of consumer behaviour. Susceptibility to compensative buying is higher among reciprocals and egoists than among persons who prefer other value orientations. According to the results of the cluster analysis, 1/3 of Poles married or in a partnership are characterised by the co-dependence of reciprocal or egoistic value orientations and compensative buying. The same conclusion can be drawn about compulsive buying—susceptibility to this type of consumer behaviour seems to be higher among reciprocals and egoists than among persons choosing other value orientations. In contrast, the prosocial value orientation appears to be an obstacle of compulsive buying: Prosocials’ susceptibility to compulsive buying is weaker compared with persons representing other value orientations. Finally, susceptibility to demonstrative buying is observable among reciprocals to a greater extent than among representatives of other value orientations. It means that the co-dependence of the reciprocal value orientation and demonstrative buying might appear among about 1/6 of Poles married or in a partnership.Reasons for the co-dependence of the particular value orientations and consumer behaviours can be looked for in specific social and cultural conditions.Firstly, relatively strong bonds between value orientations and religiosity in the Polish society might be expected. From the sociological point of view, this connection between value orientations and religiosity is quite obvious. According to Malinowski , each reThis statement by Schnabel and Groetsch is of high importance for the presented study. Compulsive, compensative, as well as demonstrative consumer behaviours might be perceived as signs of consumerism from the Christian point of view. In principle, consumerism as an idea and its different empirical symptoms such as excessive buying are disapproved by Christianity. On the other hand, the type of the prosocial value orientation corresponds with the Christian ethics appealing to the principle of the love of neighbour. Hence, susceptibility to compensative, compulsive or demonstrative buying should be lower in those societies where Christianity plays an important role. For the same reasons, prosocials in these societies should reject compensative, compulsive, and demonstrative buying to a greater extent than supporters of other types of value orientations. According to the results of the World Values Survey, the rate of Poles who define themselves as religious amounts to the level of 83%. The ratio is about 1.5–2.0 times higher compared e.g. with the USA (58%), Germany (52%), Spain (47%), or the Netherlands (42%). In total, only 10% of Poles declare that they never attend religious services. The ratio in the compared countries is even a few times higher: the Netherlands (57%), Spain (46%), Germany (41%), the USA (33%) . The relSecondly, in a sense, the correlation of value orientations and consumer behaviours was inherited from Poland’s socialist period in the 1980s characterised by a drastically insufficient degree of satisfying the citizens’ economic needs . This faThirdly, the causes of the co-dependence between particular value orientations and consumer behaviours can be found in specific upbringing styles. Specific conditions of socialisation and authoritarian or overprotective upbringing styles which lead to a distortion of an individual’s autonomy and a healthy feeling of one’s own value are mentioned as the main social reasons for susceptibility to compensative/ compulsive buying . ReasonsFourthly, the reciprocal value orientation is characteristic of persons oriented more traditionally in reference to the establishment of social relationships. In part, this type of persons belongs to the generations born in the early 1970s at the latest. They had the highest chance to internalize the reciprocal value orientation because their childhood and adolescence fell on the period before the intensive modernization processes after 1989. The generations suffered from insufficient satisfaction of their economic needs at the same time, which might lead to a specific personal value hierarchy in which materialistic values are more or less on the top . ActuallThe conducted study points to the possibility of relations existing between different types of value orientations and consumer behaviours. The obtained data confirm hypotheses H2, H3, and H4. Indeed, the stronger the reciprocal value orientation, the stronger susceptibility to compensative, compulsive as well as demonstrative buying. The stronger the egoistic orientation, the stronger susceptibility to compensative and compulsive buying. In contrast, hypothesis H1 has to be rejected; the obtained data do not indicate that the prosocial value orientation differentiates susceptibility to compensative buying.In part, the characteristic of the above presented correlations are modified in the multidimensional models. Still, materialism and self-esteem are the main factors of compulsive buying. If both variables are included in the model, the negative correlation between the prosocial value orientation and compulsive buying disappears. Furthermore, even prosocials tend towards compulsive buying if they suffer from lower self-esteem and prefer materialism. Similar conclusions can be drawn in case of the egoistic value orientation and demonstrative buying. There does not exist any bivariate correlation between both variables. If materialism is included in the model, the egoistic orientation seems to weaken susceptibility to demonstrative buying but only among men.It is worth putting the question about the future development of the correlations between the analysed types of value orientations and consumer behaviours. In total, four basic directions of the changes are characteristic of the Polish society: 1) secularization understood as an autonomization of two areas of social life–value orientations and religiosity; 2) an individual’s growing autonomy from the pressure of tradition, customs, and external authorities; 3) social change of value orientations; 4) desecularization  or reconstruction of moral bonds within the development of civic society . It remaSome limitations should be kept in mind when analysing the results of the study. Firstly, the sample of the survey embraces only the respondents who are married or in an informal partnership, which raises the question about statistical representativeness of the results for the whole society. The 2016 study conducted on the statistically representative sample of Poles aged 15 and over pointed out a 4.4% rate of compulsive buyers . BecauseSecondly, the data could be influenced by the phenomenon of social desirability bias, first of all in case of the older respondents. This effect is observable in the social research, especially if the topic of addiction is interviewed. The presented conclusions about compulsive buying base on the declarations, not on the actual behaviour, which causes a growing danger of the social desirability bias effect. This effect is probably greater in case of the older than the younger generation because the latter one is characterised by a weaker susceptibility to yielding to social control.Thirdly, the study is not longitudinal, hence, the conclusions consider the co-existence of the independent and dependent variables but not any causal relations.S1 Questionnaire(DOCX)Click here for additional data file.S2 Questionnaire(DOCX)Click here for additional data file.


Lasers distinguish themselves for the high coherence and high brightness of their radiation, features which have been exploited both in fundamental research and a broad range of technologies. However, emerging applications in the field of imaging, which can benefit from brightness, directionality and efficiency, are impaired by the speckle noise superimposed onto the picture by the interference of coherent scattered fields. We contribute a novel approach to the longstanding efforts in speckle noise reduction by exploiting a new emission regime typical of nanolasers, where low-coherence laser pulses are spontaneously emitted below the laser threshold. Exploring the dynamic properties of this kind of emission in the presence of optical reinjection we show, through the numerical analysis of a fully stochastic approach, that it is possible to tailor some of the properties of the emitted radiation, in addition to exploiting this naturally existing regime. This investigation, therefore, proposes semiconductor nanolasers as potential attractive, miniaturized and versatile future sources of low-coherence radiation for imaging. Since the first demonstration by Maiman in 1960, lasers have become indispensable light sources that enable a wide range of consumer technologies and data communication systems while also promoting fundamental research in different fields ,3,4,5, whreshold . The emehreshold ,15,16,17Laser imaging, among them, has been attracting a great deal of attention thanks to the high brightness of its radiation, strong directionality, excellent color purity and high efficiency . One addOver the decades, different technologies have been developed for speckle-free laser illumination, with most strategies based on the reduction of spatial and temporal coherence of the laser emission ,25,26, aIn order to reduce or eliminate speckle noise, different technologies have been developed for speckle-free uniform illumination, and most strategies are based on the reduction of spatial and temporal coherence of laser emission ,25,26. LFollowing this promising experimental demonstration, we focus here on a simpler system: a single nanolaser operated in the low-coherence emission regime, which naturally precedes the laser threshold. The interest resides in characterizing the potential usefulness of this intrinsic emission region, normally considered a shortcoming of ultra-small devices, to exploit its features at virtually no cost! Through simulations based on stochastic modeling of the photon emission, we numerically investigate the dynamic properties of their light in the lasing transition (threshold) region. In particular, we examine the possibility of exploiting the low coherence of the photon bursts that appear (as a form of Amplified Spontaneous Emission—ASE), with superthermal statistics  determiAs shown in 1.Different micropillar nanolasers emit independently of one another, resulting in a lack of mutual coherence; thus, immediately improving on the (low) coherence properties expected from the source.2.The useful illumination results from the direct sum of the power output by each source.3.Collective feedback could reinject light into the array through reflective (or refractive) optics, mixing the photons emitted by the individual sources ; thus, f4.Diffractive optics, engraved onto the top surface of the array, could be used to control the overall beam divergence, tailoring to the needs of the envisaged application .A second realization targets stronger lighting levels. In Obtaining uniform features across the nanolaser matrix, ensuring the same operating regime, is a challenge, but similar issues are already being addressed for neuromorphic computing , where lIn order to properly account for the statistical properties of the emission in the transition region, characterized by photon bursts ,43, we mThe numerical scheme is the same as the one implemented in ; therefoAll pump values are normalized by the so-called threshold pump  Pth=Γcβ . This pu Pth=Γcβ , should An intrinsic property of the SLS is its reliance on the radiation-matter interaction based on photon numbers. As such, it is not capable of providing direct spectral (or coherence) information, a shortcoming around which we need to develop an investigation strategy to answer questions related to low-coherence emission. Making up for this indubitable drawback, the SLS is the only existing laser model capable of predicting the (observed) pre-threshold dynamics. Thus, it is at the present time irreplaceable, in spite of the incomplete information that it can provide.Although the SLS model does not provide any information about the optical spectrum or the electric field, we can infer some of the coherence properties with the help of photon statistics. The statistical properties of laser emission can be characterized through the second-order correlation function (2)g(2). In lasbehavior , the firIn a nanolaser, the large photon bursts that precede the nanolaser threshold deplete the energy reservoir, causing their own extinction . Since c maximum  at P≈1.5ter show  that theSuperthermal statistics are a guarantee of strong bunching, but the emission of independent photon bursts extends beyond its features. Experimental measurements on a microlaser show that independent photon bursts exist until atistics . This featistics .Global considerations predict favorable conditions for illumination applications in a rather broad pump range. At the same time, the lack of phase information in all models grounded in the phenomenological description of the interaction , even whWe focus our study on the coherence properties of semiconductor nanolasers  cf. . The timThe physical change corresponds to a reduction in pulse amplitude in favor of decreased interpulse time delay. Since the population is accumulated in the time intervals with no (or little) emission, the more frequent pulses—stemming from a more efficient reinjection (due to larger feedback)—use the excess population more readily, which, therefore, cannot grow to levels that are as large as the lowest feedback. This way, it is possible to gain a degree of control on the (average) frequency with which light is shone onto the sample and on its granularity . It is interesting to notice that the average photon number decreases with increasing feedback (cf. figure caption). The figures also show a slight increase in the background (spontaneous emission contribution) for increasing feedback. The decrease in average photon number is not due to a strange effect of feedback but, rather, to the choice of operating the laser at the pump value corresponding to Finally, the autocorrelation function )(0) cf.  confirmsThe question arises naturally, at this point, whether feedback can induce interdependence and to what extent this can influence the coherence of nanolaser output. The radiofrequency spectra of signals taken in the same conditions of These considerations raise concerns about the possible instauration of coherence through the cyclic renewal of pulses through reinjection. We, therefore, resort to a more detailed analysis of the conditions under which the pulses are generated.Simultaneously extracting from the numerical code, as separate entities, the number of intracavity stimulated photons and that of reinjected (stimulated) ones, we can perform a cross-correlation analysis to investigate the presence of information transfer from previous into subsequent pulses. We ignore the spontaneous photons for two reasons: 1. their much smaller number renders the likelihood of reinjection negligible; 2. even if a spontaneously emitted photon were to stimulate a pulse, its consequent phase would be randomly distributed with respect to the other pulses. Thus, we only concentrate on the stimulated fraction.It is important to reiterate the fact that all processes are stochastic, including the reinjection; thus, the feedback percentage is to be interpreted in the sense of a probability and not as a proportionality constant. This point is crucial because there is no deterministic relationship between the returning pulse—and its arrival time—and the actual presence of a reinjected photon inside the cavity: the first reinjected photon may belong to the middle or even the tail of the pulse and, therefore, may arrive, in time, when the intracavity pulse has already developed. Throughout the paper, whenever we speak of a pulse, it is to be intended as one which starts and ends with The relationship between intracavity pulse emergence and reinjected (stimulated) photons is illustrated in One additional point about synchronicity emerges from these pictures. The intracavity pulses have random shapes, which are not maintained during the transmission through the output mirror since the process is stochastic, while free-space propagation maintains the shape of the pulse once it has escaped the cavity, the reinjection, as a stochastic process, further reshapes the reinjected pulse. Hence, no strict timing relationship can be expected in the potential synchronization between intracavity and reinjected pulses. These considerations help to understand the broad peaks in the radiofrequency spectra shown in Finally, o and f stand for “output” and “feedback”, respectively, and S and The computation of the  cross-correlation uses the standard definition ,67:(3)Corelation , where mrelation  also shorelation . It is wIn order to delve a bit deeper into the understanding of the picture, we identify the intracavity photon bursts that coincide with the coupling of an external photon into the cavity. We are starting from the assumption, illustrated by The results are summarized in Armed with all the previous considerations, which warn against larger feedback fractions, we perform an additional step in the analysis: we measure the amount of energy contained in each pulse, assuming an emission wavelength The information obtained from The orange curves show the integral of the histogram; thus, conveying information about the total amount of power carried by the weaker pulses. The largest feedback provides the fastest growth; thus, confirming the comment about the temporal uniformity of the power distribution: the 80% mark is reached, for The question about possible coherence is still not entirely settled. One piece of information, however, provides precious insight. The last column of The origin of the multiple pulses per external cavity roundtrip is grounded in the internal time constants of the laser at the pump rates that we consider and in the approximate synchronization mentioned above. Since the nanolaser can emit pulses with preferential frequency larger than the external cavity roundtrip, the different trains that appear in the output, measured as the average number of pulses in The fact that multiple trains of pulses can exist in a cavity roundtrip time suggests checking whether the observation still holds for longer feedback arms. Considering a roundtrip time The presence of “unusual”—for macroscopic lasers—spontaneous pulsing offers the possibility of obtaining low-coherence directional emission from a nanolaser. The great advantage is that this kind of emission is naturally present below the threshold and does not require any engineering effort. The features of this emission can be, however, tailored to the users’ needs by introducing a small amount of optical feedback. The analysis has shown that the latter can regularize the emission in time by introducing smaller and more frequent pulses organized in independent trains whose number depends on the length of the feedback arm. The latter can be constructed by coupling the output into an optical fiber of easily handled length (of the order of one meter) to substantially modify the power distribution.The current analysis has been based on a fully stochastic simulation of the laser operation, an important feature, since it has allowed for the proper simulation of the probabilistic nature of the transmission (in output and in reinjection) both concerning the photon number (thus the pulse shape) and the time at which the event takes place. As discussed in


Single-crystal Cu not only has high electrical and thermal conductivity, but can also be used as a promising platform for the epitaxial growth of two-dimensional materials. Preparing large-area single-crystal Cu foils from polycrystalline foils has emerged as the most promising technique in terms of its simplicity and effectiveness. However, the studies on transforming polycrystalline foil into large-area single-crystal foil mainly focus on the influence of annealing temperature and strain energy on the recrystallization process of copper foil, while studies on the effect of annealing atmosphere on abnormal grain growth behavior are relatively rare. It is necessary to carry out more studies on the effect of annealing atmosphere on grain growth behavior to understand the recrystallization mechanism of metal. Here, we found that introduction of ethanol in pure argon annealing atmosphere will cause the abnormal grain growth of copper foil. Moreover, the number of abnormally grown grains can be controlled by the concentration of ethanol in the annealing atmosphere. Using this technology, the number of abnormally grown grains on the copper foil can be controlled to single one. This abnormally grown grain will grow rapidly to decimeter-size by consuming the surrounding small grains. This work provides a new perspective for the understanding of the recrystallization of metals, and a new method for the preparation of large-area single-crystal copper foils. Single-crystal metal foils with various facet indices have attracted considerable interest due to their potential applications in electronics ,2, catalRecently, a technology has been developed to prepare large-area single-crystal copper foil by abnormal grain growth during the annealing of polycrystalline copper foil ,15,16. TThe annealing atmospheres also have an important effect on the recrystallized texture and abnormal grain growth of metal. Hydrogen, as a reductive gas, can reduce the formation energy of vacancies in the bulk which is highly critical for grain rotation , and favEthanol is often used in experiments, such as in cleaning substrates or quartz tubes, and can also be used as carbon source to prepare graphene on copper foils at low temperatures . StudyinWe used the typical contact-free method of annealing copper foils. The annealing of copper foils was carried out in a split tube furnace . The commercially available copper foils  were vertically fixed by home-made quartz holders. Then, the quartz holder with copper foil was loaded in the center of the furnace. Different amounts of ethanol , drawn by a pipette, were loaded in a ceramic boat, which was then placed at the gas inlet side of quartz tube. After the reactor was evacuated to a pressure of <5 Pa, Ar (99.999% purity) was introduced to break the vacuum to normal pressure. Subsequently, the furnace was heated up to 1060 °C within 90 min in a 1000 sccm Ar flow and then maintained for 30 min. For 70 μm-thick and 80 μm-thick copper foils, the annealing temperature and the annealing time were increased to 1070 °C and 5 h, respectively. After annealing, the furnace was opened for fast cooling. When no ethanol was introduced into the reactor, the same number and size of copper foil was load in the furnace, and then the same annealing process was performed.The crystal orientation of the prepared samples was investigated by electron backscatter diffraction  and X-ray diffraction . The morphology and surface of the samples were investigated by atomic force microscope , a scanning electron microscope , and an optical microscope .In this study, we found that ethanol can effectively induce the abnormal grain growth of copper foil during high temperature annealing. The number of the abnormally grown grains is very sensitive to the amount of ethanol in the annealing atmosphere. By controlling the amount of ethanol introduced in the annealing atmosphere, a decimeter-scale grain can be obtained on the copper foil. The EBSD and XRD were used to confirm the crystal orientation of as-obtained large grains. The as-prepared single-crystal grains are also applicable to the epitaxial growth of high-quality graphene.To highlight the influence of ethanol, we used the typical contact-free method of annealing copper foils, to eliminate or minimize the influence of other factors, such as strain energy and interface energy that arise from the interfacial contact . The conTo better illustrate the effect of ethanol on abnormal grain growth, we first annealed the copper foils in pure argon gas. The results showed no obvious abnormal growth of millimeter-level and above grains were found , no abnormally grown grain was observed from the second batch. The number of annealing batches required to eliminate the residual ethanol in the reactor increases as the amount of introduced ethanol increases. We observed that the single abnormally grown grain, which can be regarded as the first abnormally grown grain, preferentially appeared at the upper edge region of foils when the concentration of ethanol was very low . The EBSD and XRD were used to analyze the crystal orientation of large grains. The XRD 2θ scan spectra only showed two characteristic peaks of (111) and (222) crystal plans  . It was In conclusion, we have demonstrated that ethanol can affect the recrystallization process of copper foil. The abnormal grain growth appeared on the polycrystalline copper foil when ethanol was introduced into the pure argon annealing atmosphere. The number of abnormally grown grains on the copper foil can be controlled by the amount of ethanol introduced into the reactor. Moreover, the grain growth behavior is very sensitive to the amount of ethanol in the annealing atmosphere. Multiple annealing batches are required to eliminate the effect of residual ethanol in the reactor on the grain growth behavior, when the ethanol was introduced into the reactor. Furthermore, a large-sized, abnormally grown grain can be obtained on the polycrystalline copper soil by reducing the amount of ethanol introduced into the reactor to 10 μL and extending the annealing time to 2–4 h. We found that the influence of ethanol on the grain growth behavior of Cu foils decreases with the increase of the copper foil thickness, at the same concentration level of ethanol. The obtained large-area, single-crystal grain can be used as catalyst to epitaxially grow high-quality graphene.