WWF Tanzania

Abstract Aim Large trees (d.b.h. ≥ 70 cm) store large amounts of biomass. Several studies suggest that large trees may be vulnerable to changing climate, potentially leading to declining forest biomass storage. Here we determine the importance of large trees for tropical forest biomass storage and explore which intrinsic (species trait) and extrinsic (environment) variables are associated with the density of large trees and forest biomass at continental and pan‐tropical scales. Location Pan‐tropical. Methods Aboveground biomass ( AGB) was calculated for 120 intact lowland moist forest locations. Linear regression was used to calculate variation in AGB explained by the density of large trees. Akaike information criterion weights ( AICc ‐wi) were used to calculate averaged correlation coefficients for all possible multiple regression models between AGB /density of large trees and environmental and species trait variables correcting for spatial autocorrelation. Results Density of large trees explained c . 70% of the variation in pan‐tropical AGB and was also responsible for significantly lower AGB in Neotropical [287.8 (mean) ± 105.0 ( SD ) M g ha −1 ] versus Palaeotropical forests (Africa 418.3 ± 91.8 M g ha −1 ; Asia 393.3 ± 109.3 M g ha −1 ). Pan‐tropical variation in density of large trees and AGB was associated with soil coarseness (negative), soil fertility (positive), community wood density (positive) and dominance of wind dispersed species (positive), temperature in the coldest month (negative), temperature in the warmest month (negative) and rainfall in the wettest month (positive), but results were not always consistent among continents. Main conclusions Density of large trees and AGB were significantly associated with climatic variables, indicating that climate change will affect tropical forest biomass storage. Species trait composition will interact with these future biomass changes as they are also affected by a warmer climate. Given the importance of large trees for variation in AGB across the tropics, and their sensitivity to climate change, we emphasize the need for in‐depth analyses of the community dynamics of large trees.

Marine protected areas (MPAs) are a popular conservation strategy, but their impacts on human welfare are poorly understood. To inform future research and policy decisions, we reviewed the scientific literature to assess MPA impacts on five indicators of human welfare: food security, resource rights, employment, community organization, and income. Following MPA establishment, food security generally remained stable or increased in older and smaller MPAs. The ability of most fishing groups to govern MPA resources changed. Increased resource rights were positively correlated with MPA zoning and compliance with MPA regulations. Small sample sizes precluded statistical tests of the impacts of MPAs on employment, community organization, and income. Our results demonstrate that MPAs shape the social well-being and political power of fishing communities; impacts (positive and negative) vary within and among social groups; and social impacts are correlated with some--but not all--commonly hypothesized explanatory factors. Accordingly, MPAs may represent a viable strategy for enhancing food security and empowering local communities, but current practices negatively affect at least a minority of fishers. To inform policy making, further research must better document and explain variation in the positive and negative social impacts of MPAs.

Abstract In efforts to protect the world's oceans, the Convention on Biological Diversity has moved the goal of establishing marine protected areas (MPAs) to cover 10% of the ocean from 2012 to 2020. This adjustment suggests that the rush to establish MPAs without proper resources does not resolve conservation problems. In fact, such actions may create a false sense of protection that camouflages degradation of marine ecosystems on regional scales. To exemplify this phenomenon, we reviewed MPA efficacy in the Gulf of California, Mexico, where some 23,300 km 2 have been decreed as MPAs. With the exception of Cabo Pulmo National Park, MPAs have not met conservation or sustainability goals. We examined MPA budgets and foundations’ investment in the region and found that funding for management is not the limiting factor in MPA efficacy, although funding for enforcement may be deficient. We conclude that MPAs have failed because of insufficient no‐take zones, lack of enforcement, poor governance, and minimal community involvement. We need a new philosophy to implement MPAs to take advantage of the scientific knowledge and monetary investment that have been generated worldwide and ensure that they complement effective fisheries management outside their borders.

River flows connect people, places, and other forms of life, inspiring and sustaining diverse cultural beliefs, values, and ways of life. The concept of environmental flows provides a framework for improving understanding of relationships between river flows and people, and for supporting those that are mutually beneficial. Nevertheless, most approaches to determining environmental flows remain grounded in the biophysical sciences. The newly revised Brisbane Declaration and Global Action Agenda on Environmental Flows (2018) represents a new phase in environmental flow science and an opportunity to better consider the co-constitution of river flows, ecosystems, and society, and to more explicitly incorporate these relationships into river management. We synthesize understanding of relationships between people and rivers as conceived under the renewed definition of environmental flows. We present case studies from Honduras, India, Canada, New Zealand, and Australia that illustrate multidisciplinary, collaborative efforts where recognizing and meeting diverse flow needs of human populations was central to establishing environmental flow recommendations. We also review a small body of literature to highlight examples of the diversity and interdependencies of human-flow relationships-such as the linkages between river flow and human well-being, spiritual needs, cultural identity, and sense of place-that are typically overlooked when environmental flows are assessed and negotiated. Finally, we call for scientists and water managers to recognize the diversity of ways of knowing, relating to, and utilizing rivers, and to place this recognition at the center of future environmental flow assessments. This article is categorized under: Water and Life > Conservation, Management, and Awareness Human Water > Water Governance Human Water > Water as Imagined and Represented.

Abstract Sand mining (used here as a generic term that includes mining of any riverine aggregates regardless of particle size) is a global activity that is receiving increasing media attention due to perceived negative environmental and social impacts. As calls grow for stronger regulation of mining, there is a need to understand the scientific evidence to support effective management. This paper summarizes the results of a structured literature review addressing the question, “What evidence is there of impacts of sand mining on ecosystem structure, process, and biodiversity in rivers, floodplains, and estuaries?” The review found that most investigations have focused on temperate rivers where sand mining occurred historically but has now ceased. Channel incision was the most common physical impact identified; other physical responses, including habitat disturbance, alteration of riparian zones, and changes to downstream sediment transport, were highly variable and dependant on river characteristics. Ecosystem attributes affected included macroinvertebrate drift, fish movements, species abundance and community structures, and food web dynamics. Studies often inferred impacts on populations, but supporting data were scarce. Limited evidence suggests that rivers can sustain extraction if volumes are within the natural sediment load variability. Significantly, the countries and rivers for which there is science‐based evidence related to sand mining are not those where extensive sand mining is currently reported. The lack of scientific and systematic studies of sand mining in these countries prevents accurate quantification of mined volumes or the type, extent, and magnitude of any impacts. Additional research into how sand mining is affecting ecosystem services, impacting biodiversity and particularly threatened species, and how mining impacts interact with other activities or threats is urgently required.

Effective HER activity on layered double hydroxide nanosheets through a plasma etching strategy.

Abstract A hybrid LES‐RANS modelling approach is proposed. RANS is used in the near wall regions ( y + ≲60), and the turbulence is modelled with a k – ω model. LES is used in the remaining part of the flow, and the SGS turbulence is modelled with a one‐equation k sgs model. The same continuity and momentum equations are solved throughout the domain, the only difference being that the turbulent viscosity is taken from the k – ω model in the RANS region, and from the one‐equation k sgs model in the LES region. The new modelling approach is applied to two incompressible flow test cases. They are fully developed flow in a plane channel and the flow over a 2D‐hill in a channel. Copyright © 2003 John Wiley & Sons, Ltd.

Global freshwater biodiversity is declining dramatically, and meeting the challenges of this crisis requires bold goals and the mobilisation of substantial resources. While the reasons are varied, investments in both research and conservation of freshwater biodiversity lag far behind those in the terrestrial and marine realms. Inspired by a global consultation, we identify 15 pressing priority needs, grouped into five research areas, in an effort to support informed stewardship of freshwater biodiversity. The proposed agenda aims to advance freshwater biodiversity research globally as a critical step in improving coordinated actions towards its sustainable management and conservation.

Summary Wildlife is an essential component of all ecosystems. Most places in the globe do not have local, timely information on which species are present or how their populations are changing. With the arrival of new technologies, camera traps have become a popular way to collect wildlife data. However, data collection has increased at a much faster rate than the development of tools to manage, process and analyse these data. Without these tools, wildlife managers and other stakeholders have little information to effectively manage, understand and monitor wildlife populations. We identify four barriers that are hindering the widespread use of camera trap data for conservation. We propose specific solutions to remove these barriers integrated in a modern technology platform called Wildlife Insights. We present an architecture for this platform and describe its main components. We recognize and discuss the potential risks of publishing shared biodiversity data and a framework to mitigate those risks. Finally, we discuss a strategy to ensure platforms like Wildlife Insights are sustainable and have an enduring impact on the conservation of wildlife.

For magnetic resonance, the established class of intravenous contrast media is the gadolinium-based contrast agents. In the 3 decades since initial approval, these have proven in general to be very safe for human administration. However, in 2006, a devastating late adverse reaction to administration of the less stable gadolinium-based contrast agents was identified, nephrogenic systemic fibrosis. The result of actions taken by the European Medicines Agency and the US Food and Drug Administration, stratifying the agents by risk and contraindicating specific agents in severe renal dysfunction, has led to no new cases being identified in North America or Europe. Subsequently, in 2014, long-term deposition in the brain of gadolinium was first shown, after administration of 2 nonionic linear chelates, gadodiamide, and gadopentetate dimeglumine. This has led to an intense focus on the question of in vivo distribution, possible dechelation, and subsequent deposition of gadolinium, together with substantial clarification of the phenomenon as well as stratification of the agents on this basis. This review focuses on 8 critical questions regarding gadolinium deposition in the brain and body, with the answers and discussion therein important for future regulatory decisions and clinical practice. It is now clear that dechelation of gadolinium occurs in vivo with the linear agents and is responsible for this phenomenon, with key experts in the field recommending, except where there is no suitable alternative, a shift in clinical practice from the linear to macrocyclic agents. In addition, on March 10, 2017, the Pharmacovigilance and Risk Assessment Committee of the European Medicines Agency recommended suspension of the marketing authorization for 4 linear gadolinium contrast agents-specifically Omniscan, Optimark, Magnevist, and MultiHance (gadodiamide, gadoversetamide, gadopentetate dimeglumine, and gadobenate dimeglumine)-for intravenous injection. Cited in the report was convincing evidence of gadolinium deposition in the brain months after injection of these linear agents. Primovist/Eovist (gadoxetic acid disodium) will remain available, being used at a lower dose for liver imaging, because it meets an important diagnostic need. In addition, a formulation of Magnevist for intra-articular injection will remain available because of its very low gadolinium concentration.

Climate-smart agriculture (CSA) is agriculture that increases productivity, improves resilience, and mitigates climate change. Smallholder adoption of farming technology is necessary to speed the transition to CSA. Here, we assessed the determinants of adoption of five technologies that can help achieve some of the CSA outcomes in smallholder farms in Tanzania. They included: crop and livestock diversification, irrigation, application of chemical fertilizers, and agroforestry. Using data collected from 821 farming households, a multivariate probit model was employed to evaluate the determinants of adoption, allowing for examination of synergies and trade-offs between the technologies. Application of chemical fertilizers was fairly well adopted (34% of farmers), while irrigation was least adopted (26%). Some technologies, including crop diversification and irrigation, as well as application of chemical fertilizer and agro-forestry, complemented each other. Trade-offs were observed between livestock diversification and irrigation. Female control of farm resources, farm location, and household resources were major determinants of adoption. We therefore, recommend strategies that seeks to enhance building household resource as pathway for improved adoption of new technologies.

INTRODUCTION: Studies from Australia, Sweden, the United States, and elsewhere have found that paramedics experience violence in the emergency medical services (EMS) workplace. The objective of this study was to describe and explore violence experienced by paramedics in the ground ambulance setting, including types of violence experienced, by whom the violence was perpetrated, actions taken by paramedics, and effects of these episodes. METHOD: A cross-sectional study utilizing a mixed-methods paper survey was provided to a convenience sample of rural, suburban, and urban-based ground ambulance paramedics in two Canadian provinces. Paramedics were asked to describe episodes of verbal assault, intimidation, physical assault, sexual harassment, and sexual assault they were exposed to during the past 12 months. Qualitative questions inquired about the impact of these experiences. Response selections were analyzed using descriptive statistics and regression analysis, and qualitative data was analyzed using descriptive content analysis. RESULTS: A total of 1,884 paramedics were invited to participate and 1,676 responded (89.0%). Most participants (75%) reported experiencing violence in the past 12 months. The most common form of violence reported was verbal assault (67%), followed by intimidation (41%), physical assault (26%), sexual harassment (14%), and sexual assault (3%). Patients were identified as the most common perpetrators of violence. Serious sequellae were qualitatively reported. CONCLUSION: The majority of Canadian paramedics surveyed experience violence in the workplace, which can lead to serious personal and professional sequellae. Strategies should be devised and studied to reduce violent events toward paramedics and to mitigate the impact such events have on the wellbeing of paramedics.

There is a prevailing view that sarcomas arising in dermatofibrosarcoma protuberans (DFSP) have a higher risk of metastasis than ordinary DFSP, but these data are based on cases with variable and often suboptimal treatment. There has not been a large study of sarcomas arising in DFSP in which all cases were treated by wide local excision, thereby arguably altering outcome. Clinicopathologic features of 18 cases of sarcomas arising in DFSP treated by wide local excision and having follow up of at least 5 years were analyzed. An estimate of the proportion of sarcoma and DFSP was made. The number of mitotic figures and degree of CD34 immunoreactivity were assessed in each case. The cohort included 13 females and 5 males (age, 23–87 yrs; median, 47 yrs). The tumors involved the trunk (7), scalp (4), extremities (4), and inguinal region (3), and ranged from 1.5 to 7 cm (median, 4 cm). Sarcoma occurred de novo in 15 cases and in a recurrence in three. Sarcomas resembled fibrosarcoma (17) or malignant fibrous histiocytoma (1) and occupied between 20% and 80% of the tumor (median, 60%). Mitotic activity ranged from 2 to 16 per 10 high-power field (HPF; median 7 per 10 HPF) in the sarcomatous component and 0 to 3 per 10 HPF (median, 1 per 10 HPF) in the DFSP component. All tumors expressed CD34 in the DFSP component but only nine (50%) in the sarcomatous component. All patients were treated by wide local excision with negative margins; three additionally received radiation. Four patients (22%) developed recurrences, but none developed metastasis during the follow-up period of 62 months to 17 years (median, 81.5 mos). In contrast to earlier studies, we demonstrate that patients with sarcomas arising in DFSP do not have an increased risk of distant metastasis within a 5-year follow-up period, provided they are treated by wide local excision with negative margins. This probably reflects the fact that wide local excision results in eradication of local tumor, thereby eliminating the source for subsequent dissemination. However, we cannot completely exclude the possibility that tumors in which clear margins are achieved represent a less aggressive subset, as has been suggested for high-grade extremity sarcomas. Previous studies showing increased metastasis for sarcomas arising in DFSP should be re-evaluated to determine if, with treatment stratification, metastatic rate varies.

Fourteen examples of an unusual mesenchymal tumor characterized by sheets and fascicles of mitotically inactive, hemosiderin-stippled, spindled, and pleomorphic cells, situated around an angiectatic vasculature, are described. The 14 tumours developed in eight women and six men (aged 32-83 years) and ranged in size from 2.3 to 8 cm. Eleven cases presented in the subcutaneous tissues, of which eight were located in the lower extremity. All featured prominent clusters of thin-walled ectatic vessels surrounded by perivascular hyaline material representing a combination of fibrin and collagen. In three cases the perivascular hyalinization was so extensive that it constituted more than half of the total tumor area. The tumor cells were similar to those of malignant fibrous hystiocytoma but differed from them by the presence of prominent intranuclear cytoplasmic inclusions, the extreme scarcity of mitotic figures, and the occasional presence of CD-34 expression. These tumors also shared several features with neurilemomas, such as their unusual vasculature, intranuclear cytoplasmic inclusions, lack of mitotic figures, and abundance of mast cells. They could be distinguished from neurilemomas, however, by the usual presence of infiltrative margins and the absence of S-100 protein. Follow-up information on eight patients (6 months to 25 years) indicated recurrences in four cases, with one of the three patients experiencing numerous recurrences over a 25-year period. No patient has developed metastases, however. We suggest that this tumor is a low-grade sarcoma of uncertain lineage in which the vascular changes are, in part, reflective of its slow growth.

Whole-genome sequencing has provided fundamental insights into infectious disease epidemiology, but has rarely been used for examining transmission dynamics of a bacterial pathogen in wildlife. In the Greater Yellowstone Ecosystem (GYE), outbreaks of brucellosis have increased in cattle along with rising seroprevalence in elk. Here we use a genomic approach to examine Brucella abortus evolution, cross-species transmission and spatial spread in the GYE. We find that brucellosis was introduced into wildlife in this region at least five times. The diffusion rate varies among Brucella lineages (∼3 to 8 km per year) and over time. We also estimate 12 host transitions from bison to elk, and 5 from elk to bison. Our results support the notion that free-ranging elk are currently a self-sustaining brucellosis reservoir and the source of livestock infections, and that control measures in bison are unlikely to affect the dynamics of unrelated strains circulating in nearby elk populations.

Using data on Nielsen ratings for locally televised NBA basketball games, we find strong evidence that viewership increases when there is greater participation by white players. This finding controls for a wide variety of other factors that could systematically affect Nielsen ratings, and signifies the presence of customer discrimination in the market for NBA players. We also find that higher Nielsen ratings allow NBA teams to realize greater advertising revenues, meaning that the marginal revenue product of white players exceeds that of comparable black players. This factor explains much of the race‐based salary gap that exists in professional basketball.

Cholinergic afferents to the amygdala from the basal forebrain were studied using di-isopropyl fluorophosphate-AChE histochemistry in combination with retrograde tracing using various fluorescent dyes. Cells sending their axons to the amygdala and staining intensely for AChE were located mainly in the nucleus of the substantia innominata. They also were found in the ventral part of the globus pallidus, the horizontal limb of the nucleus tractus diagonalis Broca, and the nucleus interstitialis ansae lenticularis. A correspondence was established between these cells and cells staining for choline acetyltransferase by immunohistochemistry in both distribution and morphology. Non-cholinergic neurons which send their axons to the amygdala also were found in the substantia innominata complex.

To be successful, conservation practitioners and resource managers must fully integrate the effects of climate change into all planning projects. Some conservation practitioners are beginning to develop, test, and implement new approaches that are designed to deal with climate change. We devised four basic tenets that are essential in climate-change adaptation for conservation: protect adequate and appropriate space, reduce nonclimate stresses, use adaptive management to implement and test climate-change adaptation strategies, and work to reduce the rate and extent of climate change to reduce overall risk. To illustrate how this approach applies in the real world, we explored case studies of coral reefs in the Florida Keys; mangrove forests in Fiji, Tanzania, and Cameroon; sea-level rise and sea turtles in the Caribbean; tigers in the Sundarbans of India; and national planning in Madagascar. Through implementation of these tenets conservation efforts in each of these regions can be made more robust in the face of climate change. Although these approaches require reconsidering some traditional approaches to conservation, this new paradigm is technologically, economically, and intellectually feasible.

PURPOSE: Dual Energy CT (DECT) provides so-called monoenergetic images based on a linear combination of the original polychromatic images. At certain patient-specific energy levels, corresponding to certain patient- and slice-dependent linear combination weights, e.g., E = 160 keV corresponds to α = 1.57, a significant reduction of metal artifacts may be observed. The authors aimed at analyzing the method for its artifact reduction capabilities to identify its limitations. The results are compared with raw data-based processing. METHODS: Clinical DECT uses a simplified version of monochromatic imaging by linearly combining the low and the high kV images and by assigning an energy to that linear combination. Those pseudo-monochromatic images can be used by radiologists to obtain images with reduced metal artifacts. The authors analyzed the underlying physics and carried out a series expansion of the polychromatic attenuation equations. The resulting nonlinear terms are responsible for the artifacts, but they are not linearly related between the low and the high kV scan: A linear combination of both images cannot eliminate the nonlinearities, it can only reduce their impact. Scattered radiation yields additional noncanceling nonlinearities. This method is compared to raw data-based artifact correction methods. To quantify the artifact reduction potential of pseudo-monochromatic images, they simulated the FORBILD abdomen phantom with metal implants, and they assessed patient data sets of a clinical dual source CT system (100, 140 kV Sn) containing artifacts induced by a highly concentrated contrast agent bolus and by metal. In each case, they manually selected an optimal α and compared it to a raw data-based material decomposition in case of simulation, to raw data-based material decomposition of inconsistent rays in case of the patient data set containing contrast agent, and to the frequency split normalized metal artifact reduction in case of the metal implant. For each case, the contrast-to-noise ratio (CNR) was assessed. RESULTS: In the simulation, the pseudo-monochromatic images yielded acceptable artifact reduction results. However, the CNR in the artifact-reduced images was more than 60% lower than in the original polychromatic images. In contrast, the raw data-based material decomposition did not significantly reduce the CNR in the virtual monochromatic images. Regarding the patient data with beam hardening artifacts and with metal artifacts from small implants the pseudo-monochromatic method was able to reduce the artifacts, again with the downside of a significant CNR reduction. More intense metal artifacts, e.g., as those caused by an artificial hip joint, could not be suppressed. CONCLUSIONS: Pseudo-monochromatic imaging is able to reduce beam hardening, scatter, and metal artifacts in some cases but it cannot remove them. In all cases, the CNR is significantly reduced, thereby rendering the method questionable, unless special post processing algorithms are implemented to restore the high CNR from the original images (e.g., by using a frequency split technique). Raw data-based dual energy decomposition methods should be preferred, in particular, because the CNR penalty is almost negligible.

Surface exposed Ti³⁺ and lattice embedded Ti³⁺ in an optimum ratio is the determining factor for optimized photocatalytic H₂ evolution.