291 research outputs found
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The ecological effects of livestock guarding dogs (LGDs) on target and non-target wildlife
Livestock guarding dogs (LGDs) are used across the world to reduce livestock depredation by free-ranging predatory wildlife. In doing so, they reduce the need for lethal predator control and are considered beneficial for conservation. However, LGDs might be perceived as predators by wildlife and induce a multitude of both positive and negative ecological effects. We conducted a literature review to evaluate the ecological effects of LGDs and found 56 publications reporting LGDs interacting with or affecting wildlife. Featuring in 77% of the publications, LGDs were widely reported to chase and kill wildlife, leading to species43 specific behavioural responses. A total of 80 species were affected by LGDs; 11 of which are listed as Near Threatened or higher on the IUCN Red List. Of the affected species, 78% were non-target species, suggesting that any benefits arising from the use of LGDs likely occur simultaneously with unintended ecological effects. However, the frequency of LGD-wildlife interactions and the magnitude of any resulting ecological effects have rarely been quantified. More empirical studies are therefore needed to determine the net ecological outcome of LGD use, thus ensuring that negative outcomes are minimised while benefiting both farmers and wildlife
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Livestock guarding dogs enable human-carnivore coexistence: first evidence of equivalent carnivore occupancy on guarded and unguarded farms
Livestock guarding dogs (LGDs) are advocated to reduce livestock depredation on agricultural lands. However, LGDs have been proposed as excluding carnivores from guarded farms; this study is the first to test this hypothesis in an African ecosystem. We investigated carnivore occupancy (black-backed jackal, leopard and brown hyaena) from 1029 camera-trap days (126 camera locations) in relation to the presence of LGDs and a range of habitat and land-use covariates across eight South African farms, five of which utilised an LGD. Models containing LGDs had little support in explaining leopard or black backed jackal occupancy, although LGD presence had a positive relationship with brown hyaena occupancy (β = 1.14, 95% CI = 0.05, 2.23). Leopard detection was positively related to the presence of black-backed jackals (β = 1.47, 95% CI = 0.18, 2.74) and sheep (β = 1.13, 95% CI = 0.14, 2.12), whilst black-backed jackal detection was negatively related to lures (β = -1.33, 95% CI = -2.00, -0.65) and positively related to the presence of brown hyaena (β = 0.90, 95% CI = 0.43, 1.40). Previous research in this LGD population has demonstrated the cessation of livestock depredation in 91% of cases, making dog ineffectiveness unlikely to explain their lack of influence on carnivore occupancy. Our results provide the first empirical evidence based on ecological data of the capacity for LGDs to promote human-carnivore coexistence in an African agricultural context, further validating the use of specialist guarding dogs as a conservation tool of benefit to both human and wildlife populations
Ethnic differences in dissatisfaction with sexual life in patients with type 2 diabetes in a Swedish town
<p>Abstract</p> <p>Background</p> <p>The first aim of this study was to analyze whether self-reported satisfaction with one's sexual life was associated with ethnicity (Swedish and Assyrian/Syrian) in patients with type 2 diabetes. The second was to study whether the association between satisfaction with one's sexual life and ethnicity remained after controlling for possible confounders such as marital status, HbA1c, medication, and presence of other diseases.</p> <p>Methods</p> <p>This cross-sectional, questionnaire-based study was conducted at four primary health care centers in the Swedish town of Södertälje. A total of 354 persons (173 ethnic Assyrians/Syrians and 181 ethnic Swedes) participated.</p> <p>Results</p> <p>The total prevalence of self-reported dissatisfaction with one's sexual life in both groups was 49%. No significant ethnic differences were found in the outcome. In the final model, regardless of ethnicity, the odds ratio (OR) for self-reported dissatisfaction with one's sexual life in those ≥ 70 years old was 2.52 (95% CI 1.33-4.80). Among those living alone or with children, the OR was more than three times higher than for married or cohabiting individuals (OR = 3.10, 95% CI 1.60-6.00). Those with other diseases had an OR 1.89 times (95% CI 1.10-3.40) higher than those without other diseases.</p> <p>Conclusions</p> <p>The findings demonstrate that almost half of participants were dissatisfied with their sexual life and highlight the importance of sexual life to people with type 2 diabetes. This factor should not be ignored in clinical evaluations. Moreover, the findings demonstrate that it is possible to include questions on sexual life in investigations of patients with type 2 diabetes and even in other health-related, questionnaire studies, despite the sensitivity of the issue of sexuality.</p
Search for Kaluza-Klein Graviton Emission in Collisions at TeV using the Missing Energy Signature
We report on a search for direct Kaluza-Klein graviton production in a data
sample of 84 of \ppb collisions at = 1.8 TeV, recorded
by the Collider Detector at Fermilab. We investigate the final state of large
missing transverse energy and one or two high energy jets. We compare the data
with the predictions from a -dimensional Kaluza-Klein scenario in which
gravity becomes strong at the TeV scale. At 95% confidence level (C.L.) for
=2, 4, and 6 we exclude an effective Planck scale below 1.0, 0.77, and 0.71
TeV, respectively.Comment: Submitted to PRL, 7 pages 4 figures/Revision includes 5 figure
Measurement of the average time-integrated mixing probability of b-flavored hadrons produced at the Tevatron
We have measured the number of like-sign (LS) and opposite-sign (OS) lepton
pairs arising from double semileptonic decays of and -hadrons,
pair-produced at the Fermilab Tevatron collider. The data samples were
collected with the Collider Detector at Fermilab (CDF) during the 1992-1995
collider run by triggering on the existence of and candidates
in an event. The observed ratio of LS to OS dileptons leads to a measurement of
the average time-integrated mixing probability of all produced -flavored
hadrons which decay weakly, (stat.)
(syst.), that is significantly larger than the world average .Comment: 47 pages, 10 figures, 15 tables Submitted to Phys. Rev.
A new anisotropy index on trabecular bone radiographic images using the fast Fourier transform
BACKGROUND: The degree of anisotropy (DA) on radiographs is related to bone structure, we present a new index to assess DA. METHODS: In a region of interest from calcaneus radiographs, we applied a Fast Fourier Transform (FFT). All the FFT spectra involve the horizontal and vertical components corresponding respectively to longitudinal and transversal trabeculae. By visual inspection, we measured the spreading angles: Dispersion Longitudinal Index (DLI) and Dispersion Transverse Index (DTI) and calculated DA = 180/(DLI+DTI). To test the reliability of DA assessment, we synthesized images simulating radiological projections of periodic structures with elements more or less disoriented. RESULTS: Firstly, we tested synthetic images which comprised a large variety of structures from highly anisotropic structure to the almost isotropic, DA was ranging from 1.3 to 3.8 respectively. The analysis of the FFT spectra was performed by two observers, the Coefficients of Variation were 1.5% and 3.1 % for intra-and inter-observer reproducibility, respectively. In 22 post-menopausal women with osteoporotic fracture cases and 44 age-matched controls, DA values were respectively 1.87 ± 0.15 versus 1.72 ± 0.18 (p = 0.001). From the ROC analysis, the Area Under Curve (AUC) were respectively 0.65, 0.62, 0.64, 0.77 for lumbar spine, femoral neck, total femoral BMD and DA. CONCLUSION: The highest DA values in fracture cases suggest that the structure is more anisotropic in osteoporosis due to preferential deletion of trabeculae in some directions
Self Assessment in Insects: Honeybee Queens Know Their Own Strength
Contests mediate access to reproductive opportunities in almost all species of animals. An important aspect of the evolution of contests is the reduction of the costs incurred during intra-specific encounters to a minimum. However, escalated fights are commonly lethal in some species like the honeybee, Apis mellifera. By experimentally reducing honeybee queens' fighting abilities, we demonstrate that they refrain from engaging in lethal contests that typically characterize their reproductive dominance behavior and coexist peacefully within a colony. This suggests that weak queens exploit an alternative reproductive strategy and provides an explanation for rare occurrences of queen cohabitation in nature. Our results further indicate that self-assessment, but not mutual assessment of fighting ability occurs prior to and during the agonistic encounters
Distinct glutaminyl cyclase expression in Edinger–Westphal nucleus, locus coeruleus and nucleus basalis Meynert contributes to pGlu-Aβ pathology in Alzheimer’s disease
Glutaminyl cyclase (QC) was discovered recently as the enzyme catalyzing the pyroglutamate (pGlu or pE) modification of N-terminally truncated Alzheimer’s disease (AD) Aβ peptides in vivo. This modification confers resistance to proteolysis, rapid aggregation and neurotoxicity and can be prevented by QC inhibitors in vitro and in vivo, as shown in transgenic animal models. However, in mouse brain QC is only expressed by a relatively low proportion of neurons in most neocortical and hippocampal subregions. Here, we demonstrate that QC is highly abundant in subcortical brain nuclei severely affected in AD. In particular, QC is expressed by virtually all urocortin-1-positive, but not by cholinergic neurons of the Edinger–Westphal nucleus, by noradrenergic locus coeruleus and by cholinergic nucleus basalis magnocellularis neurons in mouse brain. In human brain, QC is expressed by both, urocortin-1 and cholinergic Edinger–Westphal neurons and by locus coeruleus and nucleus basalis Meynert neurons. In brains from AD patients, these neuronal populations displayed intraneuronal pE-Aβ immunoreactivity and morphological signs of degeneration as well as extracellular pE-Aβ deposits. Adjacent AD brain structures lacking QC expression and brains from control subjects were devoid of such aggregates. This is the first demonstration of QC expression and pE-Aβ formation in subcortical brain regions affected in AD. Our results may explain the high vulnerability of defined subcortical neuronal populations and their central target areas in AD as a consequence of QC expression and pE-Aβ formation
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