53 research outputs found
Impact of climate change and development scenarios on flow patterns in the Okavango River
This paper lays the foundation for the use of scenario modelling as a tool for integrated water resource management in the Okavango River basin. The Pitman hydrological model is used to assess the impact of various development and climate change scenarios on downstream river flow. The simulated impact on modelled river discharge of increased water use for domestic use, livestock, and informal irrigation (proportional to expected population increase) is very limited. Implementation of all likely potential formal irrigation schemes mentioned in available reports is expected to decrease the annual flow by 2% and the minimum monthly flow by 5%. The maximum possible impact of irrigation on annual average flow is estimated as 8%, with a reduction of minimum monthly flow by 17%. Deforestation of all areas within a 1 km buffer around the rivers is estimated to increase the flow by 6%. However, construction of all potential hydropower reservoirs in the basin may change the monthly mean flow distribution dramatically, although under the assumed operational rules, the impact of the dams is only substantial during wet years. The simulated impacts of climate change are considerable larger that those of the development scenarios (with exception of the high development scenario of hydropower schemes) although the results are sensitive to the choice of GCM and the IPCC SRES greenhouse gas (GHG) emission scenarios. The annual mean water flow predictions for the period 2020-2050 averaged over scenarios from all the four GCMs used in this study are close to the present situation for both the A2 and B2 GHG scenarios. For the 2050-2080 and 2070-2099 periods the all-GCM mean shows a flow decrease of 20% (14%) and 26% (17%) respectively for the A2 (B2) GHG scenarios. However, the uncertainty in the magnitude of simulated future changes remains high. The simulated effect of climate change on minimum monthly flow is proportionally higher
Digital volunteer networks and humanitarian crisis reporting
Digital technologies and big data are rapidly transforming humanitarian crisis response and changing the traditional roles and powers of its actors. This article looks at a particular aspect of this transformation – the appearance of digital volunteer networks – and explores their potential to act as a new source for media coverage, in addition to their already established role as emergency response supporters. I argue that digital humanitarians can offer a unique combination of speed and safe access, while escaping some of the traditional constraints of the aid-media relationship and exceeding the conventional conceptualizations of citizen journalism. Journalists can find both challenges and opportunities in the environment where multiple crisis actors are assuming some of the media roles. The article draws on interviews with humanitarian organizations, journalists, and digital volunteer networks about their understanding of digital humanitarian communication and its significance for media coverage of crises
Undocumented Worker Employment and Firm Survivability
Do firms employing undocumented workers have a competitive advantage? Using administrative data from the state of Georgia, this paper investigates the incidence of undocumented worker employment across firms and how it affects firm survival. Firms are found to engage in herding behavior, being more likely to employ undocumented workers if competitors do. Rivals' undocumented employment harms firms' ability to survive while firms' own undocumented employment strongly enhances their survival prospects. This finding suggests that firms enjoy cost savings from employing lower-paid undocumented at workers wages less than their marginal revenue product. The herding behavior and competitive effects are found to be much weaker in geographically broad product markets, where firms have the option to shift labor-intensive production out of state or abroad
Educational development between faculty and administration
This essay employs Identity Theory to explore the professional identities of educational developers, arguing that it is important to pay attention to the different saliences, or weights, that developers attach to the faculty and administrative sides of their identities
miRNA Expression in Colon Polyps Provides Evidence for a Multihit Model of Colon Cancer
Changes in miRNA expression are a common feature in colon cancer. Those changes occurring in the transition from normal to adenoma and from adenoma to carcinoma, however, have not been well defined. Additionally, miRNA changes among tumor subgroups of colon cancer have also not been adequately evaluated. In this study, we examined the global miRNA expression in 315 samples that included 52 normal colonic mucosa, 41 tubulovillous adenomas, 158 adenocarcinomas with proficient DNA mismatch repair (pMMR) selected for stage and age of onset, and 64 adenocarcinomas with defective DNA mismatch repair (dMMR) selected for sporadic (n = 53) and inherited colon cancer (n = 11). Sporadic dMMR tumors all had MLH1 inactivation due to promoter hypermethylation. Unsupervised PCA and cluster analysis demonstrated that normal colon tissue, adenomas, pMMR carcinomas and dMMR carcinomas were all clearly discernable. The majority of miRNAs that were differentially expressed between normal and polyp were also differentially expressed with a similar magnitude in the comparison of normal to both the pMMR and dMMR tumor groups, suggesting a stepwise progression for transformation from normal colon to carcinoma. Among the miRNAs demonstrating the largest fold up- or down-regulated changes (≥4), four novel (miR-31, miR-1, miR-9 and miR-99a) and two previously reported (miR-137 and miR-135b) miRNAs were identified in the normal/adenoma comparison. All but one of these (miR-99a) demonstrated similar expression differences in the two normal/carcinoma comparisons, suggesting that these early tumor changes are important in both the pMMR- and dMMR-derived cancers. The comparison between pMMR and dMMR tumors identified four miRNAs (miR-31, miR-552, miR-592 and miR-224) with statistically significant expression differences (≥2-fold change)
SARS-CoV-2 susceptibility and COVID-19 disease severity are associated with genetic variants affecting gene expression in a variety of tissues
Variability in SARS-CoV-2 susceptibility and COVID-19 disease severity between individuals is partly due to
genetic factors. Here, we identify 4 genomic loci with suggestive associations for SARS-CoV-2 susceptibility
and 19 for COVID-19 disease severity. Four of these 23 loci likely have an ethnicity-specific component.
Genome-wide association study (GWAS) signals in 11 loci colocalize with expression quantitative trait loci
(eQTLs) associated with the expression of 20 genes in 62 tissues/cell types (range: 1:43 tissues/gene),
including lung, brain, heart, muscle, and skin as well as the digestive system and immune system. We perform
genetic fine mapping to compute 99% credible SNP sets, which identify 10 GWAS loci that have eight or fewer
SNPs in the credible set, including three loci with one single likely causal SNP. Our study suggests that the
diverse symptoms and disease severity of COVID-19 observed between individuals is associated with variants across the genome, affecting gene expression levels in a wide variety of tissue types
The effects of problem-oriented policing on crime and disorder
Problem-oriented Policing (POP) was first introduced by Herman Goldstein in 1979. The
approach was one of a series of responses to a crisis in effectiveness and legitimacy in
policing that emerged in the 1970s and 1980s. Goldstein argued that police were not
being effective in preventing and controlling crime because they had become too focused
on the “means” of policing and had neglected the “goals” of preventing and controlling
crime and other community problems. Goldstein argued that the unit of analysis in
policing must become the “problem” rather than calls or crime incidents as was the case
during that period. POP has had tremendous impact on American policing, and is now
one of the most widely implemented policing strategies in the US.
To synthesize the extant problem-oriented policing evaluation literature and assess the
effects of problem-oriented policing on crime and disorder
Eligible studies had to meet three criteria: (1) the SARA model was used for a problemoriented
policing intervention; (2) a comparison group was included; (3) at least one
crime or disorder outcome was reported with sufficient data to generate an effect size.
The unit of analysis could be people or places.
Several strategies were used to perform an exhaustive search for literature fitting the
eligibility criteria. First, a keyword search was performed on an array of online abstract
databases. Second, we reviewed the bibliographies of past reviews of problem-oriented
policing. Third, we performed forward searches for works that have cited seminal
problem-oriented policing studies. Fourth, we performed hand searches of leading
journals in the field. Fifth, we searched the publications of several research and
professional agencies. Sixth, after finishing the above searches we e-mailed the list of
studies meeting our eligibility criteria to leading policing scholars knowledgeable in the
area of problem-oriented policing to ensure we had not missed any relevant studies.
For our ten eligible studies, we provide both a narrative review of effectiveness and a
meta-analysis. For the meta-analysis, we coded all primary outcomes of the eligible
studies and we report the mean effect size (for studies with more than one primary
outcome, we averaged effects to create a mean), the largest effect, and the smallest effect.
Because of the heterogeneity of our studies, we used a random effects model.
Based on our meta-analysis, overall problem-oriented policing has a modest but
statistically significant impact on reducing crime and disorder. Our results are consistent
when examining both experimental and quasi-experimental studies.
Conclusions:
We conclude that problem-oriented policing is effective in reducing crime and disorder,
although the effect is fairly modest. We urge caution in interpreting these results because
of the small number of methodologically rigorous studies on POP and the diversity of
problems and responses used in our eligible studies
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