Assessment of apparent nonstationarity in time series of annual inflow, daily precipitation, and atmospheric circulation indices: A case study from southwest Western Australia

The southwest region of Western Australia has experienced a sustained sequence of low annual inflows to major water supply dams over the past 30 years. Until recently, the dominant interpretation of this phenomenon has been predicated on the existence of one or more sharp breaks (change or jump points), with inflows fluctuating around relatively constant levels between them. This paper revisits this interpretation. To understand the mechanisms behind the changes, we also analyze daily precipitation series at multiple sites in the vicinity and time series for several indices of regional atmospheric circulation that may be considered as drivers of regional precipitation. We focus on the winter half-year for the region (May to October) as up to 80% of annual precipitation occurs during this "season". We find that the decline in the annual inflow is in fact more consistent with a smooth declining trend than with a sequence of sharp breaks, the decline is associated with decreases both in the frequency of daily precipitation occurrence and in wet-day amounts, and the decline in regional precipitation is strongly associated with a marked decrease in moisture content in the lower troposphere, an increase in regionally averaged sea level pressure in the first half of the season, and intraseasonal changes in the regional north-south sea level pressure gradient. Overall, our approach provides an integrated understanding of the linkages between declining dam inflows, declining precipitation, and changes in regional atmospheric circulation that favor drier conditions

Classification of Australian Thunderstorms using Multivariate Analyses of Large-Scale Atmospheric Variables

Lightning accompanied by inconsequential rainfall (i.e., “dry” lightning) is the primary natural ignition source for wildfires globally. This paper presents a machine-learning and statistical-classification analysis of dry and “wet” thunderstorm days in relation to associated atmospheric conditions. The study is based on daily data for lightning-flash count and precipitation from ground-based sensors and gauges and a comprehensive set of atmospheric variables that are based on ERA-Interim for the period from 2004 to 2013 at six locations in Australia. These locations represent a wide range of climatic zones (temperate, subtropical, and tropical). Quadratic surface representations and low-dimensional summary statistics were used to characterize the main features of the atmospheric fields. Four prediction skill scores were considered, and 10-fold cross validation was used to evaluate the performance of each classifier. The results were compared with those obtained by adopting the approach used in an earlier study for the U.S. Pacific Northwest. It was found that both approaches have prediction skill when tested against independent data, that mean atmospheric field quantities proved to be the most influential variables in determining dry-lightning activity, and that no single classifier or set of atmospheric variables proved to be consistently superior to its counterpart for the six sites examined here

Lightning prediction for Australia using multivariate analyses of large-scale atmospheric variables

Lightning is a natural hazard that can lead to the ignition of wildfires, disruption and damage to power and telecommunication infrastructures, human and livestock injuries and fatalities, and disruption to airport activities. This paper examines the ability of six statistical and machine-learning classification techniques to distinguish between non-lightning and lightning days at the coarse spatial and temporal scales of current general circulation models and reanalyses. The classification techniques considered were: a combination of principal component analysis and logistic regression; classification and regression trees; random forests; linear discriminant analysis; quadratic discriminant analysis; and logistic regression. Lightning flash count observations at six locations across Australia for the period 2004 to 2013 were used, together with atmospheric variables from the ERA-Interim reanalysis. Ten-fold cross validation was used to evaluate classification performance. It was found that logistic regression was superior to the other classifiers considered, and that its prediction skill is much better than climatology. The sets of atmospheric variables included in the final logistic regression models were primarily composed of spatial mean measures of instability and lifting potential, and atmospheric water content. However, the memberships of these sets varied between climatic zones

Estimating trends and seasonality in Australian monthly lightning flash counts

We present the results of a statistical analysis of lightning characteristics in mainland Australia for the period from approximately 1988 to 2012, based on monthly lightning flash count (LFC) series obtained from a network of 19 Comité Internationale des Grands Réseaux Electriques, 500 Hz peak transmission filter circuit sensors. The temporal structures of the series are examined in terms of detecting and characterizing seasonal cycles, long-term trends, and changes in seasonality over time. A generalized additive modeling approach is used to ensure that the estimated structures are determined by the data, rather than by the constraints of any assumed mathematical form for the trends and seasonal cycle. Results indicate strong seasonality at all sites, the presence of long-term trends at 16 sites, and interactions between trend and seasonality (corresponding to changes in seasonality over time) at 13 sites. The most systematic change corresponds to a progressive deepening of the seasonal cycle (i.e., an ongoing decline in winter lightning flash counts) and is most noticeable across southern Australia (south of 30°S). These results are consistent with previous analyses that have detected decreasing atmospheric instability during the austral winter since the mid-1970s. This is associated with increasing mean sea level pressure and declining rainfall

Barriers to Screening for Diabetic Retinopathy: A Scoping Review

Purpose/Background More than 34 million people in the United States have diabetes. Diabetic retinopathy (DR) is a major complication of diabetes and a leading cause of vision loss. Risk factors for diabetic retinopathy include Type 1 and Type 2 Diabetes, hypertension, smoking, and being African American or Hispanic/Latino. This scoping review seeks to analyze the current research on ways to increase vision screenings, thus reducing cases of diabetic retinopathy in adults. Methods Between September 2020 and November 2021, a search was conducted using PubMed, EBSCOhost, Medline, and CINAHL to identify articles using keywords such as diabetic retinopathy and ophthalmology. This extensive search led our group to twenty articles from different levels of evidence, which after undergoing rapid critical appraisal (RCA) left us with fifteen to be included in this scoping review. Our goal was to understand the barriers to receiving annual screening and strategies to enhance compliance with ophthalmology. Results The articles in our scoping review include systematic reviews, randomized control trials, and case-control studies. From the articles, we discovered barriers to receiving annual exams include cost, insurance, and education. We concluded that patient education along with annual referrals to ophthalmology as prevention for diabetic retinopathy is essential for reducing vision loss. Implications for Nursing Practice Based on our scoping review, we understand that multiple barriers exist that complicate compliance with annual vision screenings. Primary care providers play an essential role in providing patient education and referral to ophthalmology to decrease the prevalence of diabetic retinopathy. More research is needed on the effectiveness of interventions such as educational pamphlets in enhancing screening rates

Update on HER-2 as a target for cancer therapy: The ERBB2 promoter and its exploitation for cancer treatment

Overexpression of the ERBB2 proto-oncogene is associated with amplification of the gene in breast cancer but increased activity of the promoter also plays a significant role. Members of two transcription factor families (AP-2 and Ets) show increased binding to the promoter in over-expressing cells. Consequently, strategies have been devised to target promoter activity, either through the DNA binding sites for these factors, or through another promoter sequence, a polypurine-polypyrimidine repeat structure. The promoter has also been exploited for its tumour-specific activity to direct the accumulation of cytotoxic compounds selectively within cancer cells. Our current understanding of the ERBB2 promoter is reviewed and the status of these therapeutic avenues is discussed

Size constancy in bat biosonar?

Perception and encoding of object size is an important feature of sensory systems. In the visual system object size is encoded by the visual angle (visual aperture) on the retina, but the aperture depends on the distance of the object. As object distance is not unambiguously encoded in the visual system, higher computational mechanisms are needed. This phenomenon is termed "size constancy". It is assumed to reflect an automatic re-scaling of visual aperture with perceived object distance. Recently, it was found that in echolocating bats, the 'sonar aperture', i.e., the range of angles from which sound is reflected from an object back to the bat, is unambiguously perceived and neurally encoded. Moreover, it is well known that object distance is accurately perceived and explicitly encoded in bat sonar. Here, we addressed size constancy in bat biosonar, recruiting virtual-object techniques. Bats of the species Phyllostomus discolor learned to discriminate two simple virtual objects that only differed in sonar aperture. Upon successful discrimination, test trials were randomly interspersed using virtual objects that differed in both aperture and distance. It was tested whether the bats spontaneously assigned absolute width information to these objects by combining distance and aperture. The results showed that while the isolated perceptual cues encoding object width, aperture, and distance were all perceptually well resolved by the bats, the animals did not assign absolute width information to the test objects. This lack of sonar size constancy may result from the bats relying on different modalities to extract size information at different distances. Alternatively, it is conceivable that familiarity with a behaviorally relevant, conspicuous object is required for sonar size constancy, as it has been argued for visual size constancy. Based on the current data, it appears that size constancy is not necessarily an essential feature of sonar perception in bats

Science Models as Value-Added Services for Scholarly Information Systems

The paper introduces scholarly Information Retrieval (IR) as a further dimension that should be considered in the science modeling debate. The IR use case is seen as a validation model of the adequacy of science models in representing and predicting structure and dynamics in science. Particular conceptualizations of scholarly activity and structures in science are used as value-added search services to improve retrieval quality: a co-word model depicting the cognitive structure of a field (used for query expansion), the Bradford law of information concentration, and a model of co-authorship networks (both used for re-ranking search results). An evaluation of the retrieval quality when science model driven services are used turned out that the models proposed actually provide beneficial effects to retrieval quality. From an IR perspective, the models studied are therefore verified as expressive conceptualizations of central phenomena in science. Thus, it could be shown that the IR perspective can significantly contribute to a better understanding of scholarly structures and activities.Comment: 26 pages, to appear in Scientometric

Discovery of catalases in members of the Chlamydiales order.

Catalase is an important virulence factor for survival in macrophages and other phagocytic cells. In Chlamydiaceae, no catalase had been described so far. With the sequencing and annotation of the full genomes of Chlamydia-related bacteria, the presence of different catalase-encoding genes has been documented. However, their distribution in the Chlamydiales order and the functionality of these catalases remain unknown. Phylogeny of chlamydial catalases was inferred using MrBayes, maximum likelihood, and maximum parsimony algorithms, allowing the description of three clade 3 and two clade 2 catalases. Only monofunctional catalases were found (no catalase-peroxidase or Mn-catalase). All presented a conserved catalytic domain and tertiary structure. Enzymatic activity of cloned chlamydial catalases was assessed by measuring hydrogen peroxide degradation. The catalases are enzymatically active with different efficiencies. The catalase of Parachlamydia acanthamoebae is the least efficient of all (its catalytic activity was 2 logs lower than that of Pseudomonas aeruginosa). Based on the phylogenetic analysis, we hypothesize that an ancestral class 2 catalase probably was present in the common ancestor of all current Chlamydiales but was retained only in Criblamydia sequanensis and Neochlamydia hartmannellae. The catalases of class 3, present in Estrella lausannensis and Parachlamydia acanthamoebae, probably were acquired by lateral gene transfer from Rhizobiales, whereas for Waddlia chondrophila they likely originated from Legionellales or Actinomycetales. The acquisition of catalases on several occasions in the Chlamydiales suggests the importance of this enzyme for the bacteria in their host environment

Renal artery stenosis-when to screen, what to stent?

Renal artery stensosis (RAS) continues to be a problem for clinicians, with no clear consensus on how to investigate and assess the clinical significance of stenotic lesions and manage the findings. RAS caused by fibromuscular dysplasia is probably commoner than previously appreciated, should be actively looked for in younger hypertensive patients and can be managed successfully with angioplasty. Atheromatous RAS is associated with increased incidence of cardiovascular events and increased cardiovascular mortality, and is likely to be seen with increasing frequency. Evidence from large clinical trials has led clinicians away from recommending interventional revascularisation towards aggressive medical management. There is now interest in looking more closely at patient selection for intervention, with focus on intervening only in patients with the highest-risk presentations such as flash pulmonary oedema, rapidly declining renal function and severe resistant hypertension. The potential benefits in terms of improving hard cardiovascular outcomes may outweigh the risks of intervention in this group, and further research is needed