302 research outputs found
Relationships between spectral features, iron oxides and colours of surface soils in northern Jordan
Ground data on spectral characteristics of Jordan's soils remain sparse, which makes the interpretation of remote sensing datasets challenging. These are, however, very useful for predicting soil properties and agricultural suitability. Previous studies have shown that soil colours correlate well with degrees of weathering intensity, as indicated by magnetic parameters and dithionite‐extractable iron (Fed) contents along a climosequence in northern Jordan. This study enlarges the database by the results of 160 bulk samples that were collected systematically from the soil surface at 40 locations. In addition to soil colour and contents of Fed, we explore mean soil reflectance spectra (MSRS) measured by analytical spectral devices (ASD) and analyse the morphological conditions of the spectra referring to the effects of iron oxides on spectral behaviours. Results show a high correlation of spectral behaviours and colour variations with Fe oxides, and no correlation with soil organic carbon Corg. The influence of the Fe oxide contents is clearly apparent in the visible range (VIS). The presence of CaCO3 increases the reflectance in all spectral ranges. Six soil groups (Gr. I ‐ Gr. VI) were discerned qualitatively and quantitatively in the study area, which largely mirror the intensity of red colour expressed by redness indices
Detecting abrupt change in land cover in the eastern Hindu Kush region using Landsat time series (1988–2020)
Land cover change in the semi-arid environment of the eastern Hindu Kush region is driven by anthropogenic activities and environmental change impacts. Natural hazards, such as floods presumably influenced by climatic change, cause abrupt change of land cover. So far, little research has been conducted to investigate the spatiotemporal aspects of this abrupt change in the valleys. In order to explore the abrupt change in land cover and floods as its possible drivers in the eastern Hindu Kush, a semi-arid mountain region characterized by complex terrain, vegetation variation, and precipitation seasonality, we analyzed long-term Landsat image time series from 1988 to 2020 using Breaks For Additive Seasonal and Trend (BFAST). Overall, BFAST effectively detected abrupt change by using Landsat-derived Modified Soil Adjusted Vegetation Index (MSAVI). The results of our study indicate that approximately 95% of the study area experienced at least one abrupt change during 1988–2020. The years 1991, 1995, 1998, 2007, and 2016 were detected as the peak years, with the peaks occurring in different seasons. The annual trend of abrupt change is decreasing for the study area. The seasonality of abrupt change at the catchment level shows an increasing trend in the spring season for the southern catchments of Panjkora and Swat. The spatial distribution patterns show that abrupt change is primarily concentrated in the floodplains indicating that flooding is the primary driver of the land cover change in the region. We also demonstrated the accurate detection of past flood events (2015) based on the two case examples of Ayun, Rumbur, and Kalash valleys. The detection of the flood events was verified by fieldwork and historical high-resolution Google Earth imagery. Finally, our study provides an example of applying Landsat time series in a dry mountain region to detect abrupt changes in land cover and analyze impact of natural hazards such as floods
Aromatase gene and its effects on growth, reproductive and maternal ability traits in a multibreed sheep population from Brazil
We determined the polymorphism C242T of the aromatase gene (Cyp19) and its allelic frequency, as well as the effect of the variants on productive and reproductive traits in 71 purebred Santa Inês sheep, 13 purebred Brazilian Somali sheep, nine purebred Poll Dorset sheep, and 18 crossbred 1/2 Dorper sheep. The animals were genotyped using the PCR-RFLP technique. The influence of the animal's genotype on its performance or on the performance of its lambs was analyzed by the least square method. Another factor assessed was the importance of the animal's genotype in analysis models for quantitative breeding value estimates, and whether there were differences among the averages of breeding values of animals with different genotypes for this gene. In the sample studied, no AA individuals were observed; the AB and BB frequencies were 0.64 and 0.36, respectively. All Brazilian Somali sheep were of genotype BB. All 1/2 Dorper BB animals presented a lower age at first lambing, and the Santa Inês BB ewes presented a lower lambing interval. In these same genetic groups, AB ewes presented higher litter weight at weaning. This is evidence that BB ewes have a better reproductive performance phenotype, whereas AB ewes present a better maternal ability phenotype. However, in general, animals with genotype AB presented better average breeding values than those with genotype BB
Neuroactive steroids in depression and anxiety disorders: Clinical studies
Certain neuroactive steroids modulate ligand-gated ion channels via non-genomic mechanisms. Especially 3 alpha-reduced pregnane steroids are potent positive allosteric modulators of the gamma-aminobutyric acid type A (GABA(A)) receptor. During major depression, there is a disequilibrium of 3 alpha-reduced neuroactive steroids, which is corrected by clinically effective pharmacological treatment. To investigate whether these alterations are a general principle of successful antidepressant treatment, we studied the impact of nonpharmacological treatment options on neuroactive steroid concentrations during major depression. Neither partial sleep deprivation, transcranial magnetic stimulation, nor electroconvulsive therapy affected neuroactive steroid levels irrespectively of the response to these treatments. These studies suggest that the changes in neuroactive steroid concentrations observed after antidepressant pharmacotherapy more likely reflect distinct pharmacological properties of antidepressants rather than the clinical response. In patients with panic disorder, changes in neuroactive steroid composition have been observed opposite to those seen in depression. However, during experimentally induced panic induction either with cholecystokinine-tetrapeptide or sodium lactate, there was a pronounced decline in the concentrations of 3 alpha-reduced neuroactive steroids in patients with panic disorder, which might result in a decreased GABAergic tone. In contrast, no changes in neuroactive steroid concentrations could be observed in healthy controls with the exception of 3 alpha,5 alpha-tetrahydrodeoxycorticosterone. The modulation of GABA(A) receptors by neuroactive steroids might contribute to the pathophysiology of depression and anxiety disorders and might offer new targets for the development of novel anxiolytic compounds. Copyright (c) 2006 S. Karger AG, Basel
Portland\u27s Changing Landscape
Occasional Papers in Geography Publication No. 4
What is the nature and character of Portland? What are the conditions, changes and developments that have made it what it is? How does Portland compare with other places? What makes it unique? These are some of the question pursued in this volume.
This book contains thirteen chapters discussing various facets of Portland\u27s environmental, economy, and character. It is an up-to-date and comprehensive analysis of dynamics and change in the landscape. An overview is provided of Portland as a city and place to live, as well as its functional significance on a national and international basis.
Two threads are woven through the tapestry of these essays. One is that Portland is a big city but with many attributes of a small town. The other is the closeness and accessibility of city and nature. The challenge is how to nurture and maintain both - to have our cake and eat it too. The evidence is clear that most American cities have not been able to achieve this. Only the future can tell how Portland will fare.
The authors are all professional geographers or work in closely related fields. All have been involved with the Portland scene for a number of years and are uniquely qualified to write about these topics. While each approaches problems from his or her own perspective, the net result is a summing up, a taking stock of where we have been and where we are going. When considered as a whole the book should provide a better view than we have had of the nature and character of this special place.https://pdxscholar.library.pdx.edu/geog_occasionalpaper/1000/thumbnail.jp
Consumption patterns of sweet drinks in a population of Australian children and adolescents (2003–2008)
<p>Abstract</p> <p>Background</p> <p>Intake of sweet drinks has previously been associated with the development of overweight and obesity among children and adolescents. The present study aimed to assess the consumption pattern of sweet drinks in a population of children and adolescents in Victoria, Australia.</p> <p>Methods</p> <p>Data on 1,604 children and adolescents (4–18 years) from the comparison groups of two quasi-experimental intervention studies from Victoria, Australia were analysed<it>.</it> Sweet drink consumption (soft drink and fruit juice/cordial) was assessed as one day’s intake and typical intake over the last week or month at two time points between 2003 and 2008 (mean time between measurement: 2.2 years).</p> <p>Results</p> <p>Assessed using dietary recalls, more than 70% of the children and adolescents consumed sweet drinks, with no difference between age groups (p = 0.28). The median intake among consumers was 500 ml and almost a third consumed more than 750 ml per day. More children and adolescents consumed fruit juice/cordial (69%) than soft drink (33%) (p < 0.0001) and in larger volumes (median intake fruit juice/cordial: 500 ml and soft drink: 375 ml). Secular changes in sweet drink consumption were observed with a lower proportion of children and adolescents consuming sweet drinks at time 2 compared to time 1 (significant for age group 8 to <10 years, p = 0.001).</p> <p>Conclusion</p> <p>The proportion of Australian children and adolescents from the state of Victoria consuming sweet drinks has been stable or decreasing, although a high proportion of this sample consumed sweet drinks, especially fruit juice/cordial at both time points.</p
mtDNA heteroplasmy gives rise to a new maternal lineage in North Pacific humpback whales
Heteroplasmy in the mitochondrial genome offers a rare opportunity to track the evolution of
a newly arising maternal lineage in populations of non-model species. Here, we identified a
previously unreported mitochondrial DNA haplotype while assembling an integrated
database of DNA profiles and photo-identification records from humpback whales in
southeastern Alaska (SEAK). The haplotype, referred to as A8, was shared by only two
individuals, a mature female with her female calf, and differed by only a single base pair from
a common haplotype in the North Pacific, referred to as A-. To investigate the origins of the
A8 haplotype, we reviewed n = 1,089 electropherograms (including replicate samples) of n =
710 individuals with A- haplotypes from an existing collection. From this review, we found 20
individuals with clear evidence of heteroplasmy for A-/A8 (parental/derived) haplotypes. Of
these, 15 were encountered in SEAK, four were encountered on the Hawaiian breeding
ground (the primary migratory destination for whales in SEAK) and one was encountered in
the northern Gulf of Alaska. We used genotype exclusion and likelihood to identify one of the
heteroplasmic females as the likely mother of the A8 cow and grandmother of the A8 calf,
establishing the inheritance and germ-line fixation of the new haplotype from the parental
heteroplasmy. The mutation leading to this heteroplasmy and the fixation of the A8
haplotype provide an opportunity to document the population dynamics and regional fidelity
of a newly arising maternal lineage in a population recovering from exploitation.Funding
Support for this work was provided by a cooperative agreement between
Oregon State University and the National Park Service (Pacific West Region
Cooperative Ecosystems Study Unit Task Agreement #P12AC15004). Additional
funding was provided by the Mamie Markham Research Award, Joan Crebbin
Memorial Fellowship, Lylian Brucefield Reynolds Scholarship, Thomas G. Scott
Grant Scholarship and the Hatfield Marine Science Center Student Organization
Travel Grant.
Acknowledgements
We thank the SPLASH Steering Committee for access to haplotype information and
sighting records. A special thanks to Charles Jurasz for his insight and foresight in
documenting individual whales in southeastern Alaska. All research was conducted
under appropriate permits issued by the US National Marine Fisheries Service, in
accordance with the US Marine Mammal Protection Act and the US Endangered
Species Act, including no. 14122 issued to J.M.S., nos. 945-1499-02 and 473-1700-
00 issued to the Glacier Bay National Park, and no. 675 issued to C.S.B.Ye
Local recruitment of humpback whales in Glacier Bay and Icy Strait, Alaska, over 30 years
We provide new information on the scale at which fidelity and recruitment underlie observed increases in humpback whale Megaptera novaeangliae populations.We provide new information on the scale at which fidelity and recruitment underlie observed increases in humpback whale Megaptera novaeangliae populations. We used photoidentification records and DNA profiles from whales in Glacier Bay and Icy Strait (GBIS), southeastern Alaska (SEAK) to investigate 3 sources of population increase over 33 yr (1973−2005): local GBIS recruitment, recruitment from elsewhere in SEAK, and immigration from outside SEAK. We defined 2 temporal strata for these longitudinal records: ‘founder’ individuals identified from 1973 to 1985 (n = 74; n = 46 with DNA profiles) and ‘contemporary’ individuals identified from 2004 to 2005 (n = 171; n = 118 with DNA profiles). To distinguish between local recruitment
and recruitment from elsewhere in SEAK, we estimated the proportion of the contemporary stratum that was either a returning founder or descended from a founder female. After excluding 42 contemporary whales without a known mother or genotype to infer maternity, 73.6% of the contemporary stratum was confirmed or inferred through parentage analysis to be either a returning founder or a descendant of a founder mother. Of the 25 females with genotypes in the founder stratum, 24 (96%) were either represented in the contemporary stratum, had at least 1 descendant in the contemporary stratum, or both. We found no significant differences in microsatellite allele or mtDNA frequencies between the strata, suggesting little or no immigration from other feeding grounds. Our results highlight the importance of local habitat protection for a recovering species with culturally inherited migratory destinations.Ye
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