The dimensionality of plant–plant competition

To avoid extinction, every species must be able to exploit available resources at least as well as the other species in its community. All else being equal, theory predicts that the more distinct the niches of such co-occurring and competing species, the more species that can persist in the long run. However, both theoretical and experimental studies define a priori the nature and number of resources over which species compete. It therefore remains unclear whether or not species in empirically realistic contexts are actually exploiting all or some of the niches available to them. Here we provide a mathematical solution to this long-standing problem. Specifically, we show how to use the interactions between sets of co-occurring plant species to quantify their implied "niche dimensionality": the effective number of resources over which those species appear to be competing. We then apply this approach to quantify the niche dimensionality of 12 plant assemblages distributed across the globe. Contrary to conventional wisdom, we found that the niche dimensionality in these systems was much lower than the number of competing species. However, two high-resolution experiments also show that changes in the local environment induce a reshuffling of plant's competitive roles and hence act to increase the assemblages' effective niche dimensionality. Our results therefore indicate that homogeneous environments are unlikely to be able to maintain high diversity and also shows how environmental variation impacts species' niches and hence their opportunities for long-term survival.

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Surgery versus stereotactic radiotherapy for treatment of pulmonary metastases. A systematic review of literature

Future Science OA ◽

10.2144/fsoa-2019-0120 ◽

2020 ◽

Vol 6 (5) ◽

pp. FSO471

Author(s):

Francesco Londero ◽

William Grossi ◽

Angelo Morelli ◽

Orlando Parise ◽

Gianluca Masullo ◽

...

Keyword(s):

Systematic Review ◽

Stereotactic Radiotherapy ◽

Pulmonary Metastases ◽

A Priori ◽

Survival Rates ◽

Pulmonary Metastasectomy ◽

Review Of Literature ◽

Term Survival ◽

Mortality And Morbidity

It is not clear as to which is the best treatment among surgery and stereotactic radiotherapy (SBRT) for lung oligometastases. A systematic review of literature with a priori selection criteria was conducted on articles on the treatment of pulmonary metastases with surgery or SBRT. Only original articles with a population of patients of more than 50 were selected. After final selection, 61 articles on surgical treatment and 18 on SBRT were included. No difference was encountered in short-term survival between pulmonary metastasectomy and SBRT. In the long-term surgery seems to guarantee better survival rates. Mortality and morbidity after treatment are 0–4.7% and 0–23% for surgery, and 0–2% and 4–31% for SBRT. Surgical metastasectomy remains the treatment of choice for pulmonary oligometastases.

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Sustainability Planning for Healthcare Information Exchanges with Supplier Rebate Program

Operations Research ◽

10.1287/opre.2019.1912 ◽

2020 ◽

Vol 68 (3) ◽

pp. 793-817

Author(s):

Tharanga Rajapakshe ◽

Subodha Kumar ◽

Arun Sen ◽

Chelliah Sriskandarajah

Keyword(s):

Information Sharing ◽

Healthcare Delivery ◽

Healthcare Providers ◽

Service Model ◽

Term Survival ◽

Healthcare Information ◽

Sustainability Planning ◽

Long Run ◽

Revenue Streams

Can adopting multiple revenue streams secure long-term sustainability of HIEs? Healthcare information exchanges (HIEs) facilitate information sharing among participating healthcare practices. Despite HIEs’ pivotal role in improving healthcare delivery, many struggle to be financially sustainable in the long run. As a practical and implementable solution for this issue, this article proposes a multiperiod two-service model that improves the profitability of HIEs while retaining a sizable member pool. This study provides the guidelines for HIEs in adopting a two-service model. It also sheds light on how policymakers could intervene successfully to improve participation of healthcare providers and operations of the HIEs to guarantee long-term survival.

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Transition of Mesothelial Cell to Fibroblast in Peritoneal Dialysis: EMT, Stem Cell or Bystander?

Peritoneal Dialysis International ◽

10.3747/pdi.2014.00188 ◽

2015 ◽

Vol 35 (1) ◽

pp. 14-25 ◽

Cited By ~ 34

Author(s):

Yu Liu ◽

Zheng Dong ◽

Hong Liu ◽

Jiefu Zhu ◽

Fuyou Liu ◽

...

Keyword(s):

Peritoneal Dialysis ◽

Epithelial Mesenchymal Transition ◽

Experimental Studies ◽

Mesothelial Cell ◽

Local Environment ◽

Lineage Tracing ◽

Peritoneal Fibrosis ◽

Mesenchymal Transition

Long-term peritoneal dialysis (PD) can lead to fibrotic changes in the peritoneum, characterized by loss of mesothelial cells (MCs) and thickening of the submesothelial area with an accumulation of collagen and myofibroblasts. The origin of myofibroblasts is a central question in peritoneal fibrosis that remains unanswered at present. Numerous clinical and experimental studies have suggested that MCs, through epithelial-mesenchymal transition (EMT), contribute to the pool of peritoneal myofibroblasts. However, recent work has placed significant doubts on the paradigm of EMT in organ fibrogenesis (in the kidney particularly), highlighting the need to reconsider the role of EMT in the generation of myofibroblasts in peritoneal fibrosis. In particular, selective cell isolation and lineage-tracing experiments have suggested the existence of progenitor cells in the peritoneum, which are able to switch to fibroblast-like cells when stimulated by the local environment. These findings highlight the plastic nature of MCs and its contribution to peritoneal fibrogenesis. In this review, we summarize the key findings and caveats of EMT in organ fibrogenesis, with a focus on PD-related peritoneal fibrosis, and discuss the potential of peritoneal MCs as a source of myofibroblasts.

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Survival of the Smallest: A Study of Microenterprises in Haryana, India

Millennial Asia ◽

10.1177/0976399619900609 ◽

2020 ◽

Vol 11 (1) ◽

pp. 54-78 ◽

Cited By ~ 2

Author(s):

Surender Mor ◽

Sonu Madan ◽

Geoffrey R. Archer ◽

Arvind Ashta

Keyword(s):

Higher Education ◽

Work Engagement ◽

Capital Investment ◽

Primary Data ◽

Term Survival ◽

Business World ◽

Initial Capital ◽

Long Run ◽

Relevant Factors

The present study investigates the sustainability of microenterprises using primary data on 222 microenterprises in the informal small business segment of India. We identified relevant factors inducing entrepreneurs to sustain their business despite facing challenges emerging in the business world from time to time. The findings indicate that microenterprises with higher initial capital investment and those run by more experienced entrepreneurs have more chances for their long-run survival. The findings further indicate that the attainment of higher education is unrelated to long-term survival in the microbusiness world, perhaps because it opens more options of livelihood leading to exploration and experimentation of other areas of work engagement. The probability of long-run survival is higher in manufacturing microenterprises as compared to trading and services, likely because manufacturing experiences less volatility in this penurious context. Finally, microenterprises managed by males have better chances of long-run sustainability than female-operated microbusinesses.

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Stem Cell Therapy Post-AMI

10.1093/med/9780199544769.003.0010 ◽

2011 ◽

Author(s):

Philippe Menasché

Keyword(s):

Therapeutic Strategy ◽

Experimental Studies ◽

Left Ventricular ◽

Term Survival ◽

Paracrine Signalling ◽

Donor Cells ◽

Regeneration Of Cardiomyocytes ◽

Experimental Findings ◽

Cell Functionality

• Experimental studies suggest that bone marrow-derived stem cells can improve function of infarcted myocardium• This benefit seems to involve paracrine signalling and limitation of left ventricular remodelling rather than true regeneration of cardiomyocytes from donor cells• These experimental findings have been translated in the clinical setting into significant, although moderate, improvements in cardiac function and LV remodelling but the extent to which these benefits impact on event-free long term survival remains to be determined• Optimisation of this therapeutic strategy will require a more comprehensive characterisation of cell functionality and an improvement in the methods used in cell transfer, engraftment, survival and integration.

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The cooperative capital constraint revisited

Agricultural Finance Review ◽

10.1108/afr-11-2014-0034 ◽

2015 ◽

Vol 75 (2) ◽

pp. 253-266 ◽

Cited By ~ 12

Author(s):

Ziran Li ◽

Keri L Jacobs ◽

Georgeanne M Artz

Keyword(s):

A Priori ◽

Agricultural Cooperatives ◽

Empirical Examination ◽

Data Set ◽

Content Type ◽

Long Run ◽

Fixed Assets ◽

Capital Constraints ◽

Short Run

Purpose – There is little reason a priori to expect that a cooperative firm’s capital needs are different from a non-cooperative firm’s needs if the two firms are otherwise similar in function and size and operate within similar market economies. However, the notion that cooperatives face capital constraints that investor-owned firms (IOFs) do not is a persistent theme in the literature. The paper aims to discuss these issues. Design/methodology/approach – The authors revisit this hypothesis with an empirical examination of capital constraints in a panel data set of US agricultural supply and grain cooperatives and IOFs. Findings – The findings are mixed. While the authors find little to suggest that cooperatives face financial constraints on borrowing in the short run, relative to IOFs, the authors do find some evidence that for long-term investments, a capital constraint may exist. Originality/value – These short and long run differences have implications for the survival and growth of agricultural cooperatives. While in the short run, access to debt financing allows these firms to operative profitably, ultimately long-term large investments in technology and fixed assets will be required to maintain competitiveness in this industry.

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Privatization and survival: Evidence from a Russian firm survey

Economic Annals ◽

10.2298/eka1400043s ◽

2014 ◽

Vol 59 (200) ◽

pp. 43-60 ◽

Cited By ~ 6

Author(s):

Carsten Sprenger

Keyword(s):

Transition Economy ◽

Managerial Ownership ◽

Term Survival ◽

Price Controls ◽

Survival Status ◽

Long Run ◽

Privatized Firms ◽

Wage Arrears ◽

Firm Survey

This study is dedicated to an important aspect of the long-run performance of firms, namely their survival under rapidly changing conditions in a transition economy. The analysis is focused on the question of whether privatization and ownership structure have affected the likelihood of liquidation and bankruptcy of firms in Russia. We use a sample of 497 privatized and non-privatized firms that were surveyed in 1999-2000, and for which information was collected about their survival status and reasons for exit, such as bankruptcy, mergers and court decisions. More than 38% of the sample firms were liquidated over the period 1999 to 2013. We find that privatization and the choice of privatization option have no effect on the long-term survival of firms in Russia, but that managerial ownership lowers the likelihood of both liquidation and bankruptcy. Other transition-specific predictors of bankruptcy, such as the extent of price controls and the amount of wage arrears, affect firm exit in a significant way.

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Freshwater crabs of Vietnam: diversity and conservation

Journal of Vietnamese Environment ◽

10.13141/jve.vol6.no2.pp109-114 ◽

2014 ◽

Vol 6 (2) ◽

pp. 109-114

Author(s):

Van Tu Do

Keyword(s):

Rain Forest ◽

Agricultural Development ◽

Conservation Status ◽

Viet Nam ◽

Nam Co ◽

Term Survival ◽

Freshwater Crabs ◽

Conservation Actions ◽

High Diversity

The freshwater crab fauna of Vietnam has a high diversity and endemism, 49 species have been recorded and 42 of them are only known from this country. In addition, many species are undescribed or undiscovered while at least 10% of known species are facing extinction. Water pollution, urban, industrial and agricultural development, habitat loss and fragmentation, deforestation and overexploitation are the main threats to this fauna. The first conservation recommendation is keeping rain forest tracts large enough to maintain habitat and water quality for long-term survival of these crabs. More research on taxonomy, distribution, population dynamics, main pressures, conservation status are needed in order to assess conservation status and create efficient conservation actions for freshwater crabs in Vietnam. Khu hệ cua nước ngọt ở Việt Nam có mức độ đa dạng và đặc hữu cao với 49 loài đã được ghi nhận, trong đó có tới 42 loài chỉ được biết đến ở Việt Nam. Ngoài ra, nhiều loài cua nước ngọt còn chưa được mô tả hay chưa được khám phá, trong khi có tới 10% trong tổng số loài đã biết đang phải đối mặt với nguy cơ tuyệt chủng. Ô nhiễm môi trường nước, đô thị hóa, phát triển công nghiệp và nông nghiệp, nơi sống bị phân mảnh và mất, phá rừng cùng với khai thác quá mức là những mối đe dọa chính đối với khu hệ này. Công tác bảo tồn trước hết phải giữ cho diện tích rừng đủ lớn để duy trì chất lượng môi trường sống cho sự tồn tại lâu dài của các loài cua này. Các nghiên cứu về phân loại học, phân bố, động lực quần thể là rất cần thiết để đánh giá tình trạng bảo tồn và đưa ra những hành động bảo tồn hiệu quả cho các loài cua nước ngọt ở Việt Nam.

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Caspases and apoptosis

Essays in Biochemistry ◽

10.1042/bse0380009 ◽

2002 ◽

Vol 38 ◽

pp. 9-19 ◽

Cited By ~ 121

Author(s):

Guy S Salvesen

Keyword(s):

Cysteine Proteases ◽

Signalling Pathways ◽

Term Survival ◽

Mature Adult ◽

Intracellular Signalling Pathways ◽

Adult Cell ◽

Caspase Family ◽

Cell Fragments ◽

Pro Inflammatory Cytokines

The ability of metazoan cells to undergo programmed cell death is vital to both the precise development and long-term survival of the mature adult. Cell deaths that result from engagement of this programme end in apoptosis, the ordered dismantling of the cell that results in its 'silent' demise, in which packaged cell fragments are removed by phagocytosis. This co-ordinated demise is mediated by members of a family of cysteine proteases known as caspases, whose activation follows characteristic apoptotic stimuli, and whose substrates include many proteins, the limited cleavage of which causes the characteristic morphology of apoptosis. In vertebrates, a subset of caspases has evolved to participate in the activation of pro-inflammatory cytokines, and thus members of the caspase family participate in one of two very distinct intracellular signalling pathways.

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