12,919 research outputs found
Image Quality Assessment Based on Detail Differences
This paper presents a novel Full Reference method for
image quality assessment based on two indices measuring
respectively detail loss and spurious detail addition. These
indices define a two dimensional (2D) state in a Virtual
Cognitive State (VCS) space. The quality estimation is
obtained as a 2D function of the VCS, empirically
determined via polynomial fitting of DMOS values of
training images. The method provides at the same time
highly accurate DMOS estimates, and a quantitative
account of the causes of quality degradation
Group guided low intensity self-help for community dwelling older adults experiencing low mood : a dissertation presented in partial fulfillment of the requirements for the degree of Doctor of Clinical Psychology, Massey University, Albany, New Zealand
Depression is amongst the most common health issues affecting older adults,
however, access to evidence-based psychological treatments remains low amongst this age
group. This is due, in part, to numerous barriers that surround current mental health
treatment and delivery, which has contributed to discrepancies between treatment needs,
availability, and uptake. To address such barriers, low intensity Cognitive Behavioural
Therapies (LI-CBT) and in particular guided self-help interventions have emerged as
promising, brief, cost-effective, and evidence-based alternatives to traditional high intensity
therapies.
Recently, interventions have begun to utilise the advantages of guided LI-CBT selfhelp
within a group or class setting, thus providing both a cost-effective and time-efficient
form of treatment delivery. Of these group guided approaches, Living Life to the Full
(LLTTF) is the only intervention that primarily targets depression and has undergone
randomised effectiveness testing. While early evidence lends support for the efficacy of
LLTTF, further research is needed to extend the findings to different populations and age
groups, particularly older adults.
The current study examined the effect of the group guided version of LLTTF on
community dwelling older adults’ ratings of depression, anxiety, and quality of life.
Additionally, the relationship between older adults’ engagement with LLTTF and
improvements in their reported ratings on all primary outcome measures was evaluated.
Twenty-four older adult participants with symptoms of depression were recruited from a
New Zealand community setting. Participants completed the intervention over eight
sessions and data was collected at baseline, during each session, and at 1- and 6-week
follow-up. Data was analysed using Multilevel Modelling, implementing a multilevel (2
level), repeated measure (11 waves), single group design.
Results indicated significant improvements in participants’ symptoms of depression,
anxiety, and quality of life over time. There was no evidence of an interaction between
participants’ engagement and depression or anxiety ratings. Unexpectedly, engagement did
however interact with quality of life, demonstrating that higher levels of out-of-class
engagement with self-help content was related to significantly lower improvements in
quality of life. Finally, supplementary analyses indicated greater reductions in anxiety
symptoms amongst participants who lived with others compared to those who lived alone.
These results endorse LLTTF as a viable and effective low intensity treatment
option for depression in older adults, with additional benefits for symptoms of anxiety and
quality of life. When delivered to older adults, LLTTF could increase treatment access and
choice, contribute to the reduction of secondary mental health service load, minimise
treatment barriers, and importantly support older adults’ to manage symptoms of
depression and anxiety while remaining in communities of their choosing
The CaMKII/NMDA receptor complex controls hippocampal synaptic transmission by kinase-dependent and independent mechanisms.
CaMKII is one of the most studied synaptic proteins, but many critical issues regarding its role in synaptic function remain unresolved. Using a CRISPR-based system to delete CaMKII and replace it with mutated forms in single neurons, we have rigorously addressed its various synaptic roles. In brief, basal AMPAR and NMDAR synaptic transmission both require CaMKIIα, but not CaMKIIβ, indicating that, even in the adult, synaptic transmission is determined by the ongoing action of CaMKIIα. While AMPAR transmission requires kinase activity, NMDAR transmission does not, implying a scaffolding role for the CaMKII protein instead. LTP is abolished in the absence of CaMKIIα and/or CaMKIIβ and with an autophosphorylation impaired CaMKIIα (T286A). With the exception of NMDAR synaptic currents, all aspects of CaMKIIα signaling examined require binding to the NMDAR, emphasizing the essential role of this receptor as a master synaptic signaling hub
Tissue Determinants of Human NK Cell Development, Function, and Residence.
Immune responses in diverse tissue sites are critical for protective immunity and homeostasis. Here, we investigate how tissue localization regulates the development and function of human natural killer (NK) cells, innate lymphocytes important for anti-viral and tumor immunity. Integrating high-dimensional analysis of NK cells from blood, lymphoid organs, and mucosal tissue sites from 60 individuals, we identify tissue-specific patterns of NK cell subset distribution, maturation, and function maintained across age and between individuals. Mature and terminally differentiated NK cells with enhanced effector function predominate in blood, bone marrow, spleen, and lungs and exhibit shared transcriptional programs across sites. By contrast, precursor and immature NK cells with reduced effector capacity populate lymph nodes and intestines and exhibit tissue-resident signatures and site-specific adaptations. Together, our results reveal anatomic control of NK cell development and maintenance as tissue-resident populations, whereas mature, terminally differentiated subsets mediate immunosurveillance through diverse peripheral sites. VIDEO ABSTRACT
AMPHIBIAN DISTRIBUTION IN THE GEORGIA SEA ISLANDS: IMPLICATIONS FROM THE PAST AND FOR THE FUTURE
We summarized amphibian distributions for 12 coastal islands in Georgia, USA. Occurrence among islands was correlated with life history traits, habitats, island size, distance to other islands, and island geological age. Species’ distributions were determined from published literature. Island sizes and vegetation types were derived from 2011 Georgia Department of Natural Resources habitat maps, which included both federal and state vegetation classification systems. Species occurring on more islands tended to have greater total reproductive output (i.e., life span >4 years, and annual egg production >1,000 eggs) and adults had tolerance of brackish environs. Larger islands had greatÂer area of freshwater wetlands, predominantly short hydroperiod (<6 months). Species tied to long hydroperiod wetlands (>6 months) were more restricted in their distribution across islands. Overall, larger islands supported more species, but the correlation was weaker for geologically younger HoÂlocene islands (age <11,000 years). While Euclidean distance between islands does not necessarily preclude inter-island dispersal, inhospitable habitat for amphibians (brackish tidal marshes and creeks interspersed with wide rivers) suggests that inter-island dispersal is very limited. The paucity of recent occurrence data for amphibians in this dynamic coastal region, let alone standardized annual moniÂtoring data, hinders efforts to model species’ vulnerability in a region susceptible to sea level rise and development pressure. The most common survey method, standardized amphibian vocal surveys, will detect Anuran reproductive efforts, but is unlikely to ascertain if breeding was successful or to detect salamanders. While it will not replace actual population data, consideration of critical life-history traits and breeding habitat availability can be used to direct management to support long-term species perÂsistence in changing environs. Even common amphibians in coastal conservation areas of Georgia are vulnerable to increasing population isolation caused by unsuitable habitat
Relative pleopod length as an indicator of size at sexual maturity in slipper (Scyllarides squammosus) and spiny Hawaiian (Panulirus marginatus) lobsters
Body size at gonadal maturity is described for females of the slipper lobster (Scyllarides squammosus) (Scyllaridae) and the endemic Hawaiian spiny lobster (Panulirus marginatus) (Palinuridae) based on microscopic examination
of histological preparations of ovaries. These data are used to validate several morphological metrics (relative
exopodite length, ovigerous condition) of functional sexual maturity. Relative exopodite length (“pleopod length”) produced consistent estimates of size at maturity when evaluated with a newly derived statistical application for estimating size at the morphometric maturation point (MMP) for the population, identified as the midpoint of a sigmoid
function spanning the estimated boundaries of overlap between the largest immature and smallest adult animals.
Estimates of the MMP were related to matched (same-year) characterizations of sexual maturity based on ovigerous
condition — a more conventional measure of functional maturity previously used to characterize maturity for the two lobster species. Both measures of functional maturity were similar for the respective species and were within 5% and 2% of one another for slipper and spiny lobster,
respectively. The precision observed for two shipboard collection series of pleopod-length data indicated that the
method is reliable and not dependent on specialized expertise. Precision of maturity estimates for S. squammosus with the pleopod-length metric was similar
to that for P. marginatus with any of the other measures (including conventional evidence of ovigerous condition)
and greatly exceeded the precision of estimates for S. squammosus based on ovigerous condition alone. The two
measures of functional maturity averaged within 8% of the estimated size at gonadal maturity for the respective species. Appendage-to-body size proportions, such as the pleopod length metric, hold great promise, particularly for species of slipper lobsters like S. squammosus for which there exist no other reliable conventional morphological measures of sexual maturity. Morphometric proportions
also should be included among the factors evaluated when assessing size at sexual maturity in spiny lobster stocks;
previously, these proportions have been obtained routinely only for brachyuran crabs within the Crustacea
Racial Sorting and Neighborhood Quality
In cities throughout the United States, blacks tend to live in significantly poorer and lower-amenity neighborhoods than whites. An obvious first-order explanation for this is that an individual%u2019%u2019s race is strongly correlated with socioeconomic status (SES), and poorer households can only afford lower quality neighborhoods. This paper conjectures that another explanation may be as important. The limited supply of high-SES black neighborhoods in most U.S. metropolitan areas means that neighborhood race and neighborhood quality are explicitly bundled together. In the presence of any form of segregating preferences, this bundling raises the implicit price of neighborhood amenities for blacks relative to whites, prompting our conjecture -- that racial differences in the consumption of neighborhood amenities are significantly exacerbated by sorting on the basis of race, given the small numbers of blacks and especially high-SES blacks in many cities. To provide evidence on this conjecture, we estimate an equilibrium sorting model with detailed restricted Census microdata and use it to carry out informative counterfactual simulations. Results from these indicate that racial sorting explains a substantial portion of the gap between whites and blacks in the consumption of a wide range of neighborhood amenities -- in fact, as much as underlying socioeconomic differences across race. We also show that the adverse effects of racial sorting for blacks are fundamentally related to the small proportion of blacks in the U.S. metropolitan population. These results emphasize the significant role of racial sorting in the inter-generational persistence of racial differences in education, income, and wealth.
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