Seasonal variation of Haematobia irritans (Diptera: Muscidae) in a recently infested region of central Argentina

1997 ◽  
Vol 87 (1) ◽  
pp. 55-59 ◽  
Author(s):  
A. A. Guglielmone ◽  
O. S. Anziani ◽  
A. J. Mangold ◽  
R. E. Giorgi ◽  
M. M. Volpogni ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Relative Humidity ◽  
Late Summer ◽  
Seasonal Trend ◽  
Late Winter ◽  
Santa Fe ◽  
Saturation Deficit ◽  
Haematobia Irritans ◽  
The Mean ◽  
Inducing Factors

AbstractThe seasonal variation of adult populations of Haematobia irritans Linnaeus was monitored at Santa Fe, Argentina from August 1992 to August 1994 by weekly counts of flies on grazing heifers. Each year, flies were recorded at a density of more than two flies per heifer from August/September to the following June, with peaks of abundance in mid to late spring and late summer to mid autumn. The seasonal trend of fly numbers was best correlated with the mean temperature 4 weeks prior to each fly count (correlation indices of P<0.01 in six of the nine fly periods) followed by the previous 4 week mean saturation deficit. Rainfall and relative humidity correlated poorly with the seasonality of H. irritans. Temperature appeared crucial at the beginning (late winter) and at the end (early-mid autumn) of the fly season while its relevance diminished in the middle of the season. The percentage of heifers that were infested decreased from 80–100% in the fly season to 0–55% between fly seasons but H. irritans never disappeared from the heards, indicating that if diapause occurs at the latitude of the study area, part of the fly population was not sensitive to diapause inducing factors.

scholarly journals Contrasting recruitment seasonality of sea urchin species in Gran Canaria, Canary Islands (eastern Atlantic)

2014 ◽  
Vol 15 (3) ◽  
pp. 475 ◽  
Author(s):  
S. GARCIA-SANZ ◽  
P. G. NAVARRO ◽  
F. TUYA
Keyword(s):  
Community Structure ◽  
Seasonal Variation ◽  
Sea Urchin ◽  
Sea Urchins ◽  
Late Summer ◽  
Paracentrotus Lividus ◽  
Abundant Species ◽  
Late Winter ◽  
Gran Canaria ◽  
Arbacia Lixula

Despite sea-urchins can play an important role affecting the community structure of subtidal bottoms, factors controlling the dynamics of sea-urchin populations are still poorly understood. We assessed the seasonal variation in recruitment of three sea-urchin species (Diadema africanum, Paracentrotus lividus and Arbacia lixula) at Gran Canaria Island (eastern Atlantic) via monthly deployment of artificial collectors throughout an entire annual cycle on each of four adjacent habitat patches (seagrasses, sandy patches, ‘urchin-grazed’ barrens and macroalgal-dominated beds) within a shallow coastal landscape. Paracentrotus lividus and A. lixula had exclusively one main recruitment peak in late winter-spring. Diadema africanum recruitment was also seasonal, but recruits appeared in late summer-autumn, particularly on ‘urchin-grazed’ barrens with large abundances of adult conspecifics. In conclusion, this study has demonstrated non-overlapping seasonal recruitment patterns of the less abundant species (P. lividus and A. lixula) with the most conspicuous species (D. africanum) in the study area.

The rumenitis and liver abscess complex and vitamin A status in beef cattle

1970 ◽  
Vol 12 (2) ◽  
pp. 291-298
Author(s):  
A. C. Rowland
Keyword(s):  
Vitamin A ◽  
Late Summer ◽  
Early Spring ◽  
Agglutination Test ◽  
Late Winter ◽  
Liver Lesions ◽  
Seasonal Incidence ◽  
Vitamin A Status ◽  
The Mean ◽  
Intensively Managed

SUMMARYThe seasonal incidence of rumen and liver lesions is recorded in traditional and in intensively managed cattle, together with the vitamin A status of the two groups. Rumen lesions were observed to reach a peak in the late winter and early spring in traditional cattle, at which time the liver vitamin A levels fell to the lowest point; liver lesions reached a peak in the late summer. No specific trend was observable in rumen and liver lesions in the barley beef group. The mean levels of vitamin A were approximately one-third of those shown by the traditionally managed animals.It did not prove possible using the agglutination test to identify the sera of animals showing active hepatic necrobacillosis at the time of slaughter.

scholarly journals Influence of Varieties and Seasons upon the Mineral Nutrient Levels, of Coffee Leaves from Puerto Rico

1969 ◽  
Vol 53 (3) ◽  
pp. 177-186 ◽  
Author(s):  
Juan A. Bonnet
Keyword(s):  
Acid Soil ◽  
Late Summer ◽  
Mineral Nutrient ◽  
Late Winter ◽  
Yield Data ◽  
Significant Difference ◽  
Young Leaves ◽  
The Mean ◽  
Mean Differences ◽  
Leaf Composition

Twenty-six young coffee trees grown under shade in an acid upland soil of 2 farms were selected representing 3 varieties and 2 yield-groups. The yield data were recorded for the crop harvested in the fall of 1962 from 15 highyielding and 11 low-yielding trees. Young leaves from each tree were sampled in the late summer of 1961 and in the late winter of 1962. The following 10 essential plant nutrients were determined: N, P, K, Ca, Mg, Mn, Fe, B, Zn, and Cu; as well as 2 nonessential elements, Na and Al. The yield and leaf-composition data were analyzed statistically. The high-yielding trees produced 2.6 times as much coffee as the lowyielding ones, a highly significant difference. There was no significant difference between the mean yields of the varieties. "Highly significant" or "significant" mean differences were obtained in all the essential nutrients except zinc, in the coffee leaves, between varieties; in the nutrients: N, P, K, Ca, Mg, and B, between seasons; and only in Ca and Mg between yield-groups. The acid soil, Alonso clay, is high in exchangeable manganese and in aluminum; the coffee trees used here also contained high Mn and Al in their leaves.

Heat reactions of some Bantu tribesmen in southern Africa

1964 ◽  
Vol 19 (5) ◽  
pp. 881-884 ◽  
Author(s):  
C. H. Wyndham ◽  
N. B. Strydom ◽  
C. G. Williams ◽  
J. F. Morrison ◽  
G. A. G. Bredell ◽  
...  
Keyword(s):  
Heat Stress ◽  
Rectal Temperature ◽  
Southern Africa ◽  
Stress Test ◽  
Late Summer ◽  
Late Winter ◽  
Standard Heat ◽  
The Mean ◽  
Effective Temperatures ◽  
Physiological Reactions

Samples of 20 Bantu each from various tribes in southern Africa have been subjected in the late summer in Johannesburg to the established “standard heat-stress test” and were compared with a sample of mixed Bantu, studied in Johannesburg in the late winter. The mean rectal temperatures of the summer group were significantly lower than the mean of the winter group. Heart rates and sweat rates were not different. Intertribal comparisons revealed no significant differences in resting values or in heat reactions. An outstanding feature was that only 3 men of the 120 unacclimatized Bantu reached a rectal temperature of 104 F, and only one collapsed (this is 3% compared to the 50% of Caucasians who did not complete the test). No distinctions can be made between these Bantu tribes in their states of acclimatization in spite of the fact that some came from temperate and others from subtropical regions. The range of climates in the tribal territories is, however, small. Expressed as basic effective temperatures, the January climates—a hot, summer month—vary from 71 to 79 F in these different region physiological reactions of Bantu tribesmen Submitted on September 17, 1963

Seasonal Changes in Vitamin D Status and Bone Turnover in Healthy Irish Postmenopausal Women

2007 ◽  
Vol 77 (5) ◽  
pp. 320-325 ◽  
Author(s):  
Hill ◽  
McCarthy ◽  
Jakobsen ◽  
Lamberg-Allardt ◽  
Kiely ◽  
...  
Keyword(s):  
Vitamin D ◽  
Seasonal Variation ◽  
Bone Turnover ◽  
Postmenopausal Women ◽  
Seasonal Changes ◽  
Late Summer ◽  
Late Winter ◽  
Vitamin D Status ◽  
Old Irish ◽  
The Impact

Objectives: To examine the effect of season on biochemical markers of bone turnover in 51-to 75-year-old Irish women and to investigate whether such changes are related to vitamin D status. Design: Longitudinal observational study. Setting: Cork, Ireland (52ºN). Subjects: 76 apparently healthy, free-living postmenopausal women (aged 51–75 years), not taking any medication and free from any condition likely to affect vitamin D status or calcium/bone metabolism. Results: Serum 25-hydroxyvitamin D [S-25(OH)D] showed a clear seasonal variation with significantly higher (p < 0.001) values during late summer than late winter. Both urinary pyridinoline (Ur-Pyr) (p < 0.01) and deoxypyridinoline (Ur-Dpyr) (p < 0.001), but not serum parathyroid hormone or osteocalcin, showed a marked seasonal variation with lowest values during late-summer. Stratifying women into those with S-25(OH)D levels ≥ or < 50 nmol/L (vitamin D adequate and inadequate, respectively) during late-winter, showed that Ur-Pyr and Ur-Dpyr in both groups were significantly (p < 0.05) lower during late summer, and the magnitude of the reduction from winter to summer was similar in both groups. Conclusion: Seasonal changes in bone resorption markers appeared to be linked to seasonal changes in vitamin D status. Further research is needed to investigate the impact of these changes on risk of bone loss and fracture.

scholarly journals Survival and migration of rock ptarmigan in central Scandinavia

2019 ◽  
Author(s):  
Erlend B. Nilsen ◽  
Pål Fossland Moa ◽  
Henrik Brøseth ◽  
Hans Chr. Pedersen ◽  
Bjørn Roar Hagen
Keyword(s):  
Climate Change ◽  
Breeding Season ◽  
Large Scale ◽  
Late Summer ◽  
Late Winter ◽  
Rock Ptarmigan ◽  
The Mean ◽  
Lagopus Muta ◽  
And Migration

In a world undergoing massive declines in the distribution and abundance of many wildlife species, documenting basic ecological characteristics is often needed to be able to understand and potentially mitigate current and future pressures. Species living in alpine areas might be particularly vulnerable to climate change, in part because they are less likely to be able to migrate to new suitable areas. Here we report from a two year case study of rock ptarmigan (Lagopus muta) in central Scandinavia. Ptarmigan were captured in winter (n=84), and fitted with radio collars. We estimated the natural survival from mid-winter to late summer to be 0.55 (SE: 0.07), with no distinct differences between juveniles and adults, sex, or between the two years. Natural survival through late winter (February – April) was estimated at 0.77 (SE: 0.05), survival trough breeding season May-July at 0.65 (SE: 0.08), and harvest mortality through the February winter harvest at 9% (SE: 3%). Moreover, we documented large scale movement from the wintering grounds before the breeding season in the spring. The longest recorded movement was 79.5 km, and the mean distance from the capture site for birds still in the sample in May-July was 20.3 (SD: 18) km. We discuss the implications of the results in terms of ongoing climate change.

scholarly journals Seasonal population dynamics of Octopus vulgaris in the eastern Mediterranean

2006 ◽  
Vol 63 (1) ◽  
pp. 151-160 ◽  
Author(s):  
Stelios Katsanevakis ◽  
George Verriopoulos
Keyword(s):  
Eastern Mediterranean ◽  
Late Summer ◽  
Main Peak ◽  
Octopus Vulgaris ◽  
Late Winter ◽  
Visual Census ◽  
The Common ◽  
Specific Growth Rates ◽  
Seasonal Population ◽  
Seasonal Population Dynamics

Abstract The population density of Octopus vulgaris was measured by visual census with scuba diving in coastal areas in Greece (eastern Mediterranean). A time-variant, stage-classified, matrix population model was developed to interpret the seasonal variation of octopus stage densities and to estimate several life cycle parameters. An annual and a semi-annual periodic cycle were found in the stage densities. A main peak of benthic settlement was observed during summer and a secondary, irregular one during late autumn. Two spawning peaks were estimated, a main one during late winter–spring and a secondary one during late summer–early autumn. More than 50% of the just-settled individuals will eventually die after 3 months. Mortality rate declines, as individuals grow larger, reaches a minimum approximately 6 months after settlement, and then grows again probably because of terminal spawning. The life expectancy of recently settled individuals (<50 g) during their summer peak is approximately 5 months. The lifespan of the common octopus is estimated to be between 12 and 15 months. The octopuses' mean specific growth rates (±s.d.) in their natural environment were 1.61 ± 0.30 d−1 for 50–200 g individuals and 1.19 ± 0.31 d−1 for 200–500 g individuals.

Growth and N status of Populus in mixture with red alder on recent volcanic mudflow from Mount Saint Helens

1990 ◽  
Vol 20 (1) ◽  
pp. 84-90 ◽  
Author(s):  
Paul E. Heilman
Keyword(s):  
Late Summer ◽  
Height Growth ◽  
Phosphorus Fertilization ◽  
Cross Sectional ◽  
Red Alder ◽  
Total N ◽  
Foliar N ◽  
N Concentration ◽  
The Mean ◽  
Foliar N Concentration

Eleven months after the May 1980 eruption of Mount Saint Helens in southeastern Washington, United States, three Populus clones were planted in an experiment on the Toutle River mudflow deposit. The trees grew at an abnormally slow rate and by 3 years were overtopped by a dense stand (14 600 ± 3600 trees/ha) of red alder seeded naturally onto the site. Over the 6-year period of the study, the total N content of the soil increased an average of 56 kg•ha−1•year−1•. Foliar N concentration in Populus increased significantly from a mean late summer – early autumn value in the 2nd year (1982) of 0.69% N to a value of 2.06% N at the end of the seventh growing season. The mean annual height growth of the largest Populus averaged <0.5 m/year in the first 3 years, increasing to an average of over 1.0 m/year in the 5th and 6th years. Fertilizer treatments with N (as urea) and N + P (as urea plus treble superphosphate) placed in the soil near the individual Populus at a maximum rate of 5.3 g N/tree increased height growth in the year of fertilization (1982) and the following year (the response in height growth for the 2 years totaled 64%). After 1984, no significant effects of fertilizer on height growth, total height, or diameter were evident. Nitrogen fertilization significantly increased foliar N concentration (1.54% N with the highest N treatment vs. 0.69% N in the control) in the year of treatment only. Phosphorus fertilization had no significant effect on growth or foliar P concentration. At 6 years, only 2% of the Populustrichocarpa Torr. & Gray clone and 13% of the tallest Populus hybrid were equal to or above the mean height of alder dominants and codominants (6.2 m). Additionally, the diameter growth of Populus was severely limited: the trees had only 8% of the cross-sectional area of "normal" trees for their height. Results indicated that on sites of low N such as the mudflow, Populus may not compete satisfactorily in mixture with alder. Such behavior is in sharp contrast to sites of high N, where red alder cannot compete with Populus.

Seasonal Variation in Acute Dacriocystitis

2021 ◽  
Author(s):  
Elif Ertan ◽  
Sibel İnan ◽  
İsmet Doğan ◽  
Ümit Übeyt İnan
Keyword(s):  
Seasonal Variation ◽  
Outpatient Clinic ◽  
Clinical Picture ◽  
Infectious Agents ◽  
Lacrimal Duct ◽  
Rayleigh Test ◽  
Lacrimal Duct Obstruction ◽  
Duct Obstruction ◽  
The Mean

Abstract Objectives: Seasonal variation is possible in some medical conditions.Acute dacryocystitis is very disturbing clinical picture and can develop in any time of the year in patients with lacrimal duct obstruction. We aimed to investigate whether there is a seasonal relationship with the emergence of acute dacryocystitis.Material and Methods:The files of the patients who applied to the ophthalmology outpatient clinic with the complaints of tearing and discharge for five years and diagnosed with acute dacryocystitis were analyzed retrospectively. Age, gender, date of occurrence of the complaints and the date of diagnosis of acute dacryocystitis were recorded. In order to determine the seasonal relationship, the data regarding the number of cases who applied every month of the year were analyzed statistically by Rayleigh test.Results: The mean age of 60 patients (45 females, 15 males) included in the study was 54.70 ± 16.80 years. It was found that all patients were not equally likely to arrive at the hospital and the onset of their complaints throughout the months of the year (p <0.05). The frequency of applications was higher between May and August.Conclusion: There seems to be a seasonal relationship with the timing of the acute dacryocystitis. In our series, more acute dacryocystitis cases were encountered in the first spring-summer months. The reason for the increase of acute dacryocystitis cases in hot seasons of the year may be due to the increase in infectious agents in these seasons.

Abstract P403: Seasonal Variation in the Daily Urinary Sodium Excretion in Outpatients From the Northern Japan

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Tomoko Hashimoto
Keyword(s):  
Seasonal Variation ◽  
Sodium Excretion ◽  
Salt Intake ◽  
Sodium Intake ◽  
Urinary Sodium Excretion ◽  
Urinary Sodium ◽  
Reliable Estimate ◽  
Significant Difference ◽  
The Mean ◽  
Northern Japan

Although the daily urinary sodium excretion (UNaV) is considered to provide the most reliable estimate of the daily sodium intake, it may be affected by salt loss due to sweating in summer. However, theseasonal variation in the daily UNaV associated with a normal lifestyle is unknown. This study was performed in 348 outpatients from the Morioka region during three seasons: summer(summer 1), winter, and the following summer (summer 2). The daily UNaV (g salt/day) was estimated by the second morning urine method three times during each season. Seasonal variation was defined as a significant trend across the three seasons together with a significant difference between winter and both summers. In women, the daily UNaV was higher in winter (11.8±3.0 g salt/day) than in summer 1 (11.2±2.9g salt/day) or summer 2 (11.0±2.9 g salt/day). In contrast, there was no marked seasonal variation in men. An analysis stratified by age (4 quartiles) identified seasonal variation in the older 2 quartiles of women (aged ≧68 years). In these women, the mean seasonal difference in the daily UNaV was 0.9 g of salt/day for both winter vs. summer 1 and winter vs. summer 2, while it was 0.1-0.8 g of salt/day in the other groups. Seasonal variation in the daily UNaV only occurred in older female patients and was relatively small. This is evidence for restricting salt intake throughout the year and should reassure patients who are anxious about salt loss due to sweating in summer.

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