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Introduction: For patients with ST-elevation myocardial infarction (STEMI), time is myocardium. The sooner STEMI patients receive a definitive intervention, the better their outcomes. The first point of contact with the healthcare system for STEMI patients is either via Emergency Medical Services (EMS), or self-transportation to an Emergency Department (ED). Despite a reduced time to definitive intervention, STEMI patients who use EMS have increased mortality compared to those who self-transport. In an effort to optimize STEMI care pathways, we characterized variations in modes of presentation of STEMI patients in our region. Methods: This study used a retrospective cohort design from a regional STEMI registry. Patients presenting to Hamilton Health Sciences between January 1, 2016, and December 31, 2018 meeting STEMI criteria were included in our analyses. Self-transport patients were analyzed from two academic EDs in Hamilton, Ontario. One hospital was PCI capable and the other, non-PCI capable. Patients transferred from other health regions were excluded from our analyses. Dichotomous variables were compared using χ2 tests. Group means were compared using the Student t-test. Results: Eight hundred and seventy-one patients were included in the analysis, including 675 EMS users, and 196 self-transporting to EDs. Patients self-transporting to EDs were younger (61.5 v. 64.6 y, p < 0.002) and more often male (82.6 v. 69.2%, p < 0.0002) compared to EMS users. There was a non-significant trend towards an increased rate of all STEMI patients self-transporting in the summer months compared to the winter (63 of 215 in summer v. 41 of 185 in winter, 29.3 v. 22.2%, p = 0.10). Comparative analysis between both hospitals yielded an increased rate of self-transportation to the PCI-capable hospital in the summer months compared to winter (46 v. 28, 23.2 v. 16.3%, p = 0.09), but not the other hospital (18 v. 13, 10.6 v. 8.3%, p = 0.57). The majority of self-transporting patients came from postal codes bordering each hospital, and the different rates of self-transportation between hospitals were not associated with recent specialist follow up at those sites. Conclusion: Seasonal trends in modes of presentation in STEMI patients may present an opportunity to optimize STEMI care pathways through resource utilization and patient education. A larger dataset and possible multicenter analysis should be done to determine if significance is obtained with larger sample size.
Sexual differences in behaviours are often affected by the difference in individual interests between the sexes: growth in males and egg production in females. Some hermit crabs show sexual differences in shell use patterns during the reproductive season. In the non-reproductive season, however, when both sexes are focused on increasing growth, this sexual difference is expected to be reduced. In this study, we compared the pattern of shell use in the hermit crab Pagurus minutus between seasons, while focusing on the effects of shell shape on growth or egg production. As we predicted, sexual differences in shell use in P. minutus showed seasonal change. In the non-reproductive season, both sexes appeared to use shells well suited for growth. In the reproductive season, sexual differences became more evident, especially in larger solitary crabs and guarding pairs; males monopolized round-type shells such as those of Umbonium moniliferum, whereas more than 80% of females relied on high-spired Batillaria-type shells such as those of Batillaria zonalis. A lack of advantage for egg number in females using Batillaria-type shells suggests that female shell use is explained by factors other than maximizing clutch size. Both sexes can moult during the reproductive season, and larger body size is advantageous for reproduction. Given that Batillaria-type shells resulted in a lower growth increment and males have an advantage in shell fights in congeneric crabs, our findings suggest the importance of intersexual competition for shells and female compromise in determining the seasonal change of shell use patterns in P. minutus.
This study focused on the spirurid nematode Mastophorus muris in water voles (Arvicola amphibius) trapped in three regions in southern Sweden during spring and fall 2013. The collection of water voles formed part of a larger project (EMIRO) on the cestode Echinococcus multilocularis in rodents. The voles’ stomach contents were examined for the presence of M. muris. Prevalence, mean abundance and mean intensity of infection were calculated. A generalized linear model model was used to examine the effects of sex, functional group, season and region on the number of M. muris individuals in each vole. Forty-seven of 181 (26%) voles were infected with M. muris, with up to 74 worms each. The overall mean intensity (worms per infected vole) was 15 (95% CI 10–21), and abundance (mean number of worms in all voles) was 4 (95% CI 2–6). Model output indicated a significant effect of season and region with respect to abundance of nematode infection, which was independent of sex and functional group of the investigated host.
Otitis externa is the inflammation of the external auditory canal. The disease is common and shows a seasonal variation with a greater incidence in warmer months. Pseudomonas aeruginosa is a common pathogen in otitis externa and in this retrospective study, we show a corresponding seasonal variation in the proportional incidence of P. aeruginosa isolates from otitis externa in South East England. In total 7770 patients were diagnosed with otitis externa over a period of 9 years from January 2008 to December 2016. P. aeruginosa was isolated from 2802 patients (proportional incidence of 36%). Incidence was higher in the months of August, September and October and in patients between 5 and 15 years of age. We postulate a combination of increased contact with water during warm weather in the holiday season and increased rainfall in the preceding season as a putative mechanism for the seasonal trends.
To investigate seasonal variations of vitamin D status at different latitudes and if these changes are accompanied by corresponding variations in certain health parameters in children living in a broad latitudinal range in Iran.
In total, 530 apparently healthy children aged 5–18 years were randomly selected from six regions of Iran with a latitudinal gradient from 29°N to 37·5°N. All anthropometric and biochemical assessments were performed twice during a year (summer, winter). High BMI (Z-score >1), low HDL cholesterol (<40 mg/dl, males; <50 mg/dl, females) and high TAG (>150 mg/dl) were considered cardiometabolic risk factors.
Serum 25-hydroxyvitamin D (25(OH)D) showed between-season variation, with significantly higher concentrations (mean (sd)) in summer v. winter (43 (29) v. 27 (18) nmol/l; P<0·001). Change of circulating 25(OH)D between summer and winter was negatively correlated with change of BMI (r=−0·16; P<0·001), TAG (r=−0·09; P=0·04) and total cholesterol (r=−0·10; P=0·02) and directly correlated with change of height-for-age Z-score (r=0·09; P=0·04). Multiple stepwise linear regression analysis (β; 95 % CI) showed that winter serum 25(OH)D (−0·3; −0·4, −0·2; P<0·001), gender (boys v. girls: 9·7; 5·2, 14·1; P<0·001) and latitude (>33°N v. <33°N: 4·5; 0·09, 9·0; P=0·04) were predictors of change of serum 25(OH)D between two seasons.
Summertime improvement of vitamin D status was accompanied by certain improved cardiometabolic risk factors, notably serum TAG, total cholesterol and BMI, in children.
An effective management plan for invasive herb populations must consider the potential for regeneration from the soil seedbank. To test this potential, we examined two species, Japanese stiltgrass and garlic mustard, at deciduous forest sites in southeastern Ohio. Seeds were buried in nylon mesh bags and recovered at regular intervals over 24 mo. Recovered seeds were tested for germination and viability. Burial was replicated on north- and south-facing slopes to test for environmental control of dormancy state. Stiltgrass seeds experienced severe mortality in the soil, rarely surviving the full 24 mo. Stiltgrass showed fractional germination in the lab ranging from 86% to 89% of viable seeds in late spring (the season of natural seedling emergence) to complete nongermination in winter. Most garlic mustard seeds survived through the experimental period (82% and 88% survival across 24 mo) with consistently low mortality (0% to 13%) unrelated to season. Slope aspect had no significant effect on survival or dormancy state in either species. Extrapolation of garlic mustard mortality implies that reproduction would need to be suppressed for a substantial period (perhaps >10 yr) to ensure eradication of a population. In stiltgrass, rapid seed mortality suggests that control can be achieved in 2 to 4 yr.
Climate change is projected to increase the burden of food insecurity (FI) globally, particularly among populations that depend on subsistence agriculture. The impacts of climate change will have disproportionate effects on populations with higher existing vulnerability. Indigenous people consistently experience higher levels of FI than their non-Indigenous counterparts and are more likely to be dependent upon land-based resources. The present study aimed to understand the sensitivity of the food system of an Indigenous African population, the Batwa of Kanungu District, Uganda, to seasonal variation.
A concurrent, mixed methods (quantitative and qualitative) design was used. Six cross-sectional retrospective surveys, conducted between January 2013 and April 2014, provided quantitative data to examine the seasonal variation of self-reported household FI. This was complemented by qualitative data from focus group discussions and semi-structured interviews collected between June and August 2014.
Ten rural Indigenous communities in Kanungu District, Uganda.
FI data were collected from 130 Indigenous Batwa Pygmy households. Qualitative methods involved Batwa community members, local key informants, health workers and governmental representatives.
The dry season was associated with increased FI among the Batwa in the quantitative surveys and in the qualitative interviews. During the dry season, the majority of Batwa households reported greater difficulty in acquiring sufficient quantities and quality of food. However, the qualitative data indicated that the effect of seasonal variation on FI was modified by employment, wealth and community location.
These findings highlight the role social factors play in mediating seasonal impacts on FI and support calls to treat climate associations with health outcomes as non-stationary and mediated by social sensitivity.
Worldwide there are substantial differences within and between countries in aggression and violence. Although there are various exceptions, a general rule is that aggression and violence increase as one moves closer to the equator, which suggests the important role of climate differences. While this pattern is robust, theoretical explanations for these large differences in aggression and violence within countries and around the world are lacking. Most extant explanations focus on the influence of average temperature as a factor that triggers aggression (The General Aggression Model), or the notion that warm temperature allows for more social interaction situations (Routine Activity Theory) in which aggression is likely to unfold. We propose a new model, CLimate, Aggression, and Self-control in Humans (CLASH), that helps us to understand differences within and between countries in aggression and violence in terms of differences in climate. Lower temperatures, and especially larger degrees of seasonal variation in climate, call for individuals and groups to adopt a slower life history strategy, a greater focus on the future (vs. present), and a stronger focus on self-control. The CLASH model further outlines that slow life strategy, future orientation, and strong self-control are important determinants of inhibiting aggression and violence. We also discuss how CLASH differs from other recently developed models that emphasize climate differences for understanding conflict. We conclude by discussing the theoretical and societal importance of climate in shaping individual and societal differences in aggression and violence.
A 9-year time-series of genotyped human campylobacteriosis cases from the Manawatu region of New Zealand was used to investigate strain-type seasonality. The data were collected from 2005 to 2013 and the samples were multi-locus sequence-typed (MLST). The four most prevalent clonal complexes (CCs), consisting of 1215 isolates, were CC48, CC21, CC45 and CC61. Seasonal decomposition and Poisson regression with autocorrelated errors, were used to display and test for seasonality of the most prevalent CCs. Of the four examined CCs, only CC45 showed a marked seasonal (summer) peak. The association of CC45 with summer peaks has been observed in other temperate countries, but has previously not been identified in New Zealand. This is the first in-depth study over a long time period employing MLST data to examine strain-type-associated seasonal patterns of C. jejuni infection in New Zealand.
Studying seasonal hunting patterns can be critical for developing sound actions for conservation and public health. As availability of funds to implement conservation policy is limited, it is essential to focus efforts during the most critical times of year. During July 2011–June 2012 I recorded direct observations of hunting of forest mammals, and conducted daily 24-hour recall surveys (2 weeks per month over 11 months: August 2011–June 2012), and interviews of all households in a focal village on the Masoala Peninsula of Madagascar to investigate (1) what drives seasonal hunting patterns and (2) how seasonal variation in consumption of wildlife and domestic meat affects native species and people. There is marked seasonal variation in hunting of forest mammals and in the consumption of fish and domesticated livestock on the Masoala Peninsula. Hunters target bushpigs Potamochoerus larvatus and tenrec and lemur species during the austral winter (March–August), whereas more native and introduced carnivorans, fish and domesticated livestock are consumed during the austral summer (September–February). The results suggest that seasonal variation in hunting patterns is driven by the physical and behavioural characteristics of prey rather than seasonal scarcity of alternative meat. Seasonal hunting and meat consumption on the Masoala Peninsula may amplify the negative impact of hunting on native carnivorans and tenrecs (which are hunted when they are pregnant and lactating), and the positive impact of consumption of lemurs, bushpigs and tenrecs on human health. This study highlights an important aspect of hunting on the Masoala: the decision whether or not to hunt is made independently of decisions regarding when to hunt particular species.
Cryptosporidium infects millions of people worldwide causing acute gastroenteritis, but despite its remarkable epidemiological and economic impact, information on the epidemiological trends of human cryptosporidiosis is still scarce in most countries. Here we investigate a panel of 486 cases collected in Galicia (NW Iberian Peninsula) between 2000 and 2008, which sheds new light on the epidemiology in this region of the South Atlantic European façade. Incidence rates in Galicia are one order of magnitude higher than those reported in other regions of Spain, suggesting that this parasite remains largely underdiagnosed in this country, and are also larger than those typical of other European countries with available data. Two species dominate our dataset, Cryptosporidium hominis (65%) and C. parvum (34%). The sex ratio of patients infected by either species was 0·5, but C. hominis was significantly more common in younger males. C. parvum infections were more acute and required more specialized medical attention, which suggests a differential adaptation of each species to human hosts. The parasites display strong seasonal and geographical variation. C. parvum incidence peaked during summer and was mainly detected in rural areas while C. hominis infections were more frequent in autumn and exhibited a more even geographical distribution. Such differences probably reflect their distinct sources of infection – C. parvum is mainly zoonotic and C. hominis anthroponotic – and the effects of climatic variables, like temperature and rainfall.
We describe the seasonal variation of acute toxoplasmosis in the United States. Acute toxoplasmic lymphadenopathy (ATL) can be a surrogate of acute toxoplasmosis in patients in whom the date of onset of lymphadenopathy matches the window of acute infection predicted by serological tests performed at a reference laboratory. We used the electronic database of the Palo Alto Medical Foundation Toxoplasma Serology Laboratory (PAMF-TSL) (1997–2011) to identify cases of ATL. We tested the uniformity of distribution of ATL cases per month, across the 12 calendar months, using circular statistics uniformity tests. We identified 112 consecutive cases of ATL. The distribution of cases was not uniform across the 12 calendar months. We observed the highest peak of cases in December and a second highest peak in September. Similar months were identified in patients with acute toxoplasmosis in rural areas in France. The results were similar when we performed weighted analyses, weighting for the total number of Toxoplasma gondii IgG tests performed per month in the PAMF-TSL laboratory. This is the largest study to date of the seasonal variation of ATL in the United States. Physicians should advise high-risk individuals to avoid risk factors associated with T. gondii infections especially around those months.
The spatial and temporal variations of planktonic cnidarians were studied across the inner continental shelf (≤40 m) off the State of Paraná in southern Brazil. Monthly zooplankton samples were taken between November 1997 and March 1999 at five stations. The holoplanktonic Liriope tetraphylla and Muggiaea kochi dominated during the entire period, comprising >80% of the specimens. The coast–ocean gradient became evident due to a near-coastal (≤20 m) assemblage formed by L. tetraphylla, Solmaris corona and meroplanktonic medusae, and a distinct outer (25–40 m) assemblage formed by the medusae Corymorpha gracilis and Aglaura hemistoma and siphonophores. The estuarine runoff during warm rainy periods lowered the salinity (~30) at the inner stations (1, 2 and 3), providing appropriate conditions for the estuarine/coastal species. Wind-driven onshore advection of outer-shelf species to the inner isobaths occurred from late autumn to winter, when the rainfall decreased and salinity increased (>35). Population peaks occurred in both summer and winter at the inner stations. For most species, the seasonal patterns were inconsistent with other studies conducted in the Southern Brazilian Bight, suggesting irregular and unpredictable seasonal distributions of abundance. Whereas in high-latitude ecosystems the dynamics of cnidarian populations follows the seasonal productivity cycle, here, complex hydrographic processes seem to be more important in determining the structure and seasonal dynamics of this community.
Phenotyping of genetic resources remains the bottleneck in the characterization of genetic resources, since the advent of modern next-generation sequencing technologies has made genotyping much more cost- and time-effective. This article reports on the phenotyping of agriculturally important traits in perennial ryegrass (Lolium perenne). In the present study, water-soluble carbohydrate (WSC), crude protein and dry matter contents were recorded for 1320 individuals, pooled into 132 samples from 33 perennial ryegrass ecotypes and cultivars at five different harvest time points across the 2004 growing season. While, in general, the cultivars had higher WSC contents than the ecotypes, individual ecotypes did show potential to be used in breeding programmes, as they had higher values than all other accessions at particular cutting time points. In correlation analyses, positive relationships were observed between dry matter and glucose contents both early and late in the growing season. Principal components analysis allowed the split either between cultivars and ecotypes or between tetraploid cultivars and the rest of the accessions at four of the five cutting time points. In the analysis of variance, cutting time was the most significant factor influencing the variation in traits.
The seasonal variation of the inshore fish assemblage of Anegada Bay, North Patagonia, Argentina is described here. Three areas were seasonally sampled from 2007 to 2009 by means of a gang of bottom gill-nets. We found 21 coastal fish species, but species richness and fish number and weight changed throughout the year. The six species classified as dominant have national and regional value for artisanal and recreational fishing and were responsible for the seasonal variation in the fish assemblage. Both cluster and non-metric multidimensional scaling analyses based on fish number and fish weight indicated two major sample groups encompassing spring and summer (the warmer seasons) and autumn and winter (the colder seasons). The fish assemblage had higher species richness, dominance and abundance during the warmer seasons than during the colder seasons in the same years and at the same sites. Water temperature was the main environmental factor structuring the fish assemblage in Anegada Bay. We suggest that partial breeding migration toward the bay during warmer months could explain the seasonal pattern observed. Nevertheless, variation in temperature conditions agreed well with the pattern of seasonal changes, leading to an interaction between abiotic and biotic influences in determining the variability in this seasonal fish assemblage. We conclude that an understanding of species temporal and spatial patterns in areas of high ecological and economic value, as exemplified by Anegada Bay, are essential for the implementation of a management approach oriented toward ecosystem sustainability.
This article reviews the political economy of Manchuria under the rule of Zhang Zuolin, which resulted in the economic instability that occurred during the winter of 1928. One can conjecture that the economic instability did not occur only because of the arbitrariness of the political and military regional government. The instability appears to be related to an ongoing seasonal demand for monies, which was relatively high between the months of September and March, since it corresponded to the period of commerce in soybeans − the region's main economic activity −, the migration of seasonal workers, and also the festive period of the Chinese New Year. The analysis was conducted based on primary materials published by the South Manchuria Railway Company, such as currency issuance and the variation of the exchange rate of the major currencies in circulation among foreign and Chinese currencies.
To validate an FFQ to assess antioxidant intake in overweight postmenopausal women.
A seventy-four-item antioxidant 1-month FFQ was developed based on major antioxidant sources in the American diet. Forty overweight postmenopausal women participated in a 9-month observational study and completed four sets of FFQ and 7 d food record (7dFR) every 3 months. Twelve-hour fasting blood was collected for plasma antioxidant measurement at the first visit.
Forty overweight postmenopausal women.
Spearman correlation coefficients of 1-month antioxidant intake estimated from the first set of FFQ and 7dFR ranged from 0·34 to 0·87, except for γ-tocopherol. The proportion of participants categorized into the extremely opposite tertiles averaged 7 %. Significant correlations were observed for diet–plasma vitamin C, α-tocopherol and carotenoids (P < 0·05). No time effect was observed on the dietary antioxidant intakes estimated from four 7dFR and four FFQ. Dietary antioxidants estimated from averaged four 7dFR showed moderate to high correlation with those estimated from averaged four FFQ and from each FFQ collected every 3 months. Bland–Altman plots did not show any systematic bias. Averaged misclassifications were below 10 % between these two instruments.
These findings attested a reasonable validity and a good acceptance of this 1-month FFQ in assessing both short-term and long-term diverse antioxidant intakes in these overweight postmenopausal women. The use of this FFQ in associating antioxidant intake with disease risk needs further investigation.
To analyse temporal distributions of microplankton populations and relationships to environmental conditions in marine ecosystems, a dataset of microplankton communities was investigated using a range of statistical methods. A total of 164 microplankton species comprising 100 microalgae and 64 ciliates were identified from 120 samples, respectively. Both planktonic microalga and ciliate assemblages showed temporal patterns and were significantly correlated between their temporal variations in abundance. The microplankton communities were characterized by 14 ciliates (e.g. Strombidium sulcatum, Tintinnopsis tubulosoides and Strombidium cheshiri) and 18 microalgae (e.g. Skeletonema costatum and Alexandrium tamarense). Multiple regression analyses showed that the interspecies correlations among these dominant species represented a complex network with a clear seasonal shift. Temporal pattern of microplankton communities was significantly correlated with the environmental variables such as temperature, salinity and nitrate nitrogen. The results suggest the clear species distribution and temporal dynamics of microplankton communities in response to environmental changes, and multivariate statistical approaches were a useful tool to reveal the species distribution patterns and complex microplanktonic interspecies correlations in marine ecosystems.
A 30-year study of the estuarine population of yellow eel, Anguilla anguilla, abundance in Bridgwater Bay, Somerset, UK, shows that the population number has collapsed. Since 1980, the decline has averaged 15% per year. The abundance of eel in 2009 is estimated at only 1% of that in 1980. This is one of the greatest systematically quantified crashes of a fish population ever reported. Collections of eels impinged on cooling water filter screens were made monthly at Hinkley Point power station between 1980 and 2010 and from Oldbury power station between 1996 and 1998. Eels are always present in the Severn Estuary, although there are large seasonal variations in abundance. At Oldbury, in the upper estuary, eels are least abundant in January. In contrast, in the outer estuary in Bridgwater Bay, eels are most abundant between November and March. The size-distribution of yellow eels ranged from <200 to >700 mm indicating an age-range since the glass eel stage of 2 to >25 years. The mean size-range has not changed since the 1980s indicating that the population collapse is not caused by a sudden recruitment failure. It is suggested that there has been a continual long-term failure of recruitment to compensate for losses. The reason for this is unidentified, but is unlikely to be changes in the North Atlantic Oscillation or other natural environmental variability. A major effort to improve eel survival to adulthood is required if this species is not to gently fade to extinction. This would likely involve a cessation of elver fishing, a reduction in the volume of estuarine water extracted for power station cooling and other purposes during which eels are entrained and killed, and the removal of obstructions which increase mortality during migration.
The temporal and spatial variability in population dynamics of the European crab Carcinus maenas (L.) was studied between June 2003 and September 2007 in the Mondego estuary. An extreme climate event (extreme drought) occurred in 2004 and 2005 with a low freshwater flow discharge into the estuary, leading to an increase in salinity. Juveniles' recruitment was continuous throughout each year with a high proportion of young recruits being recorded in the spring of 2005. The proportion of green crabs clearly increased from the mouth to the upstream areas and the proportion of crabs actually in moult followed the same pattern. Parasitization by the endoparasitic barnacle, Sacculina carcini was observed, principally at the mouth of the estuary. The C. maenas population showed a regular size–frequency distribution and structure for both sexes during the study. Secondary production (P) of C. maenas estimated for the 4-year study period was different between years though, P/B ratios were similar during the whole study period. During the drought period, catches of the crab recruits were higher, particularly in the spring, probably due to the increase in salinity, which emphasizes the importance of these extreme events in controlling the abundances of coastal populations.