Complexity and Adaptivity in Supply Networks: Building Supply Network Theory Using a Complex Adaptive Systems Perspective*

Supply networks are composed of large numbers of firms from multiple interrelated industries. Such networks are subject to shifting strategies and objectives within a dynamic environment. In recent years, when faced with a dynamic environment, several disciplines have adopted the Complex Adaptive System (CAS) perspective to gain insights into important issues within their domains of study. Research investigations in the field of supply networks have also begun examining the merits of complexity theory and the CAS perspective. In this article, we bring the applicability of complexity theory and CAS into sharper focus, highlighting its potential for integrating existing supply chain management (SCM) research into a structured body of knowledge while also providing a framework for generating, validating, and refining new theories relevant to real‐world supply networks. We suggest several potential research questions to emphasize how a CAS perspective can help in enriching the SCM discipline. We propose that the SCM research community adopt such a dynamic and systems‐level orientation that brings to the fore the adaptivity of firms and the complexity of their interrelations that are often inherent in supply networks.     

Increased visceral adiposity index associated with sexual dysfunction in men

Objective: Visceral adipose index (VAI) is a novel parameter for the evaluation of visceral obesity. As we know that obesity is a risk factor for erectile dysfunction (ED). So, in this study, we compared the VAI levels between the men with ED and without ED.

Materials and method: A total of 177 men were included in the study. Ninety-five men with ED and 82 men without ED (control). All men were evaluated for ED by Index of Erectile Function-5 items (IIEF-5). VAI levels were calculated using body mass index, high density lipoprotein and tryglyceride levels.

Results: Mean age was 53.5 (38–69) in men who have ED and 53.1 (34–69) in control. The men with ED had higher body mass index (BMI), triglyceride (TG) levels, higher waist circumference (WC) and lower high-density lipoprotein-cholesterol (HDL-C) levels. Mean VAI level was 5.18?±?2.50 in study group and 3.47?±?1.76 in control goup, respectively. VAI levels were statistically higher in men with ED (p?Discussion: The simplicity of WC and BMI measurement and TG and HDL assessment, make VAI an easily applicable index for the evaluation of visceral fat dysfunction. VAI can be useful index for the evaluation and calculation of erectile dysfunction risk.     

A comparison of the parameter estimation methods for bimodal mixture Weibull distribution with complete data

Bimodal mixture Weibull distribution being a special case of mixture Weibull distribution has been used recently as a suitable model for heterogeneous data sets in many practical applications. The bimodal mixture Weibull term represents a mixture of two Weibull distributions. Although many estimation methods have been proposed for the bimodal mixture Weibull distribution, there is not a comprehensive comparison. This paper presents a detailed comparison of five kinds of numerical methods, such as maximum likelihood estimation, least-squares method, method of moments, method of logarithmic moments and percentile method (PM) in terms of several criteria by simulation study. Also parameter estimation methods are applied to real data.     

Manipulation via Endowments in Exchange Markets with Indivisible Goods

We consider exchange markets with heterogeneous indivisible goods. We are interested in exchange rules that are efficient and immune to manipulations via endowments (either with respect to hiding or destroying part of the endowment or transferring part of the endowment to another trader). We consider three manipulability axioms: hiding-proofness, destruction-proofness, and transfer-proofness. We prove that no rule satisfying efficiency and hiding-proofness (which together imply individual rationality) exists. For two agents with separable and responsive preferences, we show that efficient, individually rational, and destruction-proof rules exist. However, for some profiles of separable preferences, no rule is efficient, individually rational, and destruction-proof. In the case of transfer-proofness the compatibility with efficiency and individual rationality for the two-agent case extends to the unrestricted domain. If there are more than two agents, for some profiles of separable preferences, no rule is efficient, individually rational, and transfer-proof.     

TRANSITION OF INTERNATIONAL SCIENCE,TECHNOLOGY, ENGINEERING,AND MATHEMATICS STUDENTS TO THE U.S. LABOR MARKET: THE ROLE OF VISA POLICY

I analyze how visa policies affect international students' transition to the U.S. labor market. The Optional Practical Training (OPT) program permits international students to work via a student visa for a limited period after graduation before obtaining a work visa—an uncertain process due to the binding visa cap. I find that the extension in the length of OPT terms for students in science, technology, engineering, and mathematics (STEM) increases their likelihood of initially staying in the United States and using OPT. This result suggests that uncertainties about obtaining work visas hinder international STEM students' participation in the U.S. labor market. (JEL J61, K37, I23).     

‘Strategic (dis)obedience’: Female entrepreneurs reflecting on and acting upon patriarchal practices

It has been suggested that entrepreneurship is a form of emancipation and social change for women. We adopt a more comprehensive view by considering micro‐emancipation at the level of both agency and identity of women entrepreneurs in patriarchal and Islamic societies. We borrow from organization studies literature to draw on the notions of the dynamic and ongoing process between dominators (i.e., men of the patriarchal family) and the dominated (i.e., women entrepreneurs). In this process micro‐emancipation and active obedience are intertwined. For this purpose, we contextualize the study in the United Arab Emirates, where men of the family regulate women's agency and identity. The men of the family are not only the gatekeepers of societal culture, but also the potential supporters for women to navigate the societal arrangements. By adopting an interpretive approach, we analyse the narratives of Emirati female entrepreneurs in their early stages of becoming an entrepreneur who engage in strategic (dis)obedience. The article contributes to the literature on micro‐emancipation in the context of gender and entrepreneurship.     

Evaluating the distribution of invasive woody vegetation around riparian corridors in relation to land use

Invasive species have been causing important and irreversible impacts to native species and communities of ecosystems. They distort ecosystem functions by degrading forest lands, wetlands, and agricultural habitats and replace the native vegetation and reduce biodiversity, forest productivity, and suitable wildlife habitat. To address disturbances caused by invasive species occurrence, further information is needed regarding the occurrence, extent, and dispersal of invasive species and how land use may increase the spread of these species. The objective of this study was to find the frequency and dominance of three invasive species common to riparian areas of east Alabama: Ligustrum sinense (Chinese privet), Elaeagnus pungens (silverthorn), and Triadica sebifera (Chinese tallow tree). Surveys of these species in riparian forests in and around Auburn, Alabama were conducted to show the relative extent of these shrubs and their relation to urban land use. It was expected to see the highest levels of invasive species in the city center with decreasing levels radiating outward into rural areas. Another objective was how urban land use may affect the presence-absence and prevalence of these non-native plant species within study sites. The results showed that around the city center and suburban lands, cover of both Chinese privet and silverthorn tended to increase. In contrast, Chinese tallow tree density percent cover showed an opposite trend with landscapes close to city center often having slightly less cover. This study shows that urban land use may be an important association with distribution of invasive plant species.     

Visceral adiposity index is associated with benign prostatic enlargement in non-diabetic patients: a cross-sectional study

Objective: To evaluate the association between visceral adiposity index (VAI) - a novel indicator for the assessment of visceral adipose tissue and prostate enlargement in non diabetic patients.

Material and methods: Four hundred patients who were admitted to the Urology clinic between January and December 2014 with complaints of BPH(benign prostatic hyperplasia )/LUTS(male lower urinary tract symptoms)were enrolled in this cross-sectional study. Patients were divided into two groups according to their prostate volume and international prostate symptom score (IPSS) value. They were compared in terms of age, body mass index (BMI), VAI, prostate volume, PSA, post micturional residual volume (PMRV), uroflowmetry Q max value, triglyceride (TG), high density lipoprotein-cholesterol (HDL-C) and fasting blood sugar (FBS).

Results: Although univariate analyses reveal that age, BMI, waist circumference (WC), FBS, TG, HDL-C level and TG/HDL ratio were correlated with prostate volume, only age [1.125 OR (1.088–1.164), p?=?.00001], BMI [1.119 OR (1.040–1.204), p?=?.003], TG [1.043 OR (1.016–1.071), p?=?.002], HDL-C [0.923 OR (0.860–0.990), p?=?.025] and VAI [1.194 OR (1.110–1.305), p?=?.011] were statistically significant in multivariate analysis. A positive correlation was found between VAI value and prostate volume in the Spearman correlation test (r?=?0.29, p?=?.00001). The calculated area under the curve (AUC) for prostate volumes of 30, 40 and 50?ml were 0.680 (0.621–0.738), 0.625 (0.570–0.681) and 0.590 (0.528–0.652), respectively.

Conclusion: Our study revealed a positive correlation between VAI and prostate volume. Our results are needed to be tested with well-designed randomized prospective cohort studies.     

Comparison of the effectiveness of IPSS and VPSS without any help in LUTS patients: a prospective study

Aim: To compare the correlation of visual prostate symptom score (VPSS) and international prostate symptom score (IPSS). To investigate the effect of educational level and age in the responses to VPSS and IPSS.

Method: Three hundred and nine patients who gave consent and applied via LUTS to our institution were included in this study. They were requested to fill IPSS and VPSS. The patients were divided into two groups as middle-aged and elderly with a cutoff point of 65?years. They were divided into six groups based on educational level. SPSS was used for the statistical evaluation.

Results: The mean age of the patients was 61.5?±?8.9?years. The correlation was found between IPSS and VPSS (p?p?=?.332 and .138, respectively). No difference was found between the middle-aged and elderly groups in terms of the rates of inability to answer IPSS and VPSS (p?=?.177 and .681, respectively).

Conclusions: There is a correlation between VPSS and IPSS. VPSS can be used as an auxiliary or alternative tool instead of IPSS in evaluating LUTS; however, has no superiority to IPSS in elderly group. Currently, the best option to exclude bias in illiterate group is VPSS.