Parental effort of American kestrels: the role of variation in brood size

2003 ◽  
Vol 81 (5) ◽  
pp. 852-860 ◽  
Author(s):  
Russell D Dawson ◽  
Gary R Bortolotti
Keyword(s):  
Brood Size ◽  
Size Variation ◽  
Parental Effort ◽  
Proximate Determinant ◽  
American Kestrels ◽  
Experimental Variation ◽  
Proximate Determinants ◽  
Proximate Factor ◽  
And Control

Brood size has the potential to determine the allocation of resources between parents and offspring, as well as influence the relative contributions of each sex to parental effort. However, it is unclear whether brood size is the proximate determinant of parental effort, or conversely whether parental effort is the proximate factor to which brood size is adjusted. If brood size determines parental effort, then theory suggests that parental effort should vary with experimental changes in brood size. In contrast, if parental effort determines brood size, then parental effort is expected to be independent of experimental variation in brood size. To distinguish between these hypotheses, we experimentally reduced brood sizes of American kestrels (Falco sparverius). Our results suggest that male parents responded to brood-size variation and adjusted their provisioning behaviour accordingly. Conversely, female parents did not adjust provisioning in response to brood size, and as a result, offspring in reduced broods received more food on a per-nestling basis. However, condition and survival of offspring were similar in reduced broods and control young, which may have been the result of larger food requirements of small broods, owing to increased thermoregulatory costs compared with control broods. Female parents with reduced broods also did not brood offspring more often, further suggesting that females do not respond to variation in brood size. We conclude that the proximate determinants of parental effort are sex-specific in American kestrels: for males, brood size determines behaviour, whereas for females, behaviour may be a proximate factor determining brood size.

The proximate effects of food supply on intraclutch egg-size variation in American kestrels

1996 ◽  
Vol 74 (1) ◽  
pp. 118-124 ◽  
Author(s):  
Karen L. Wiebe ◽  
Gary R. Bortolotti
Keyword(s):  
Food Supply ◽  
Egg Size ◽  
Size Variation ◽  
Food Supplementation ◽  
Laying Order ◽  
American Kestrels ◽  
Good Body Condition ◽  
Adaptive Explanation ◽  
Food Shortages

Egg size can be an important determinant of offspring survival in birds. We measured eggs from 275 clutches of wild American kestrels (Falco sparverius) to study the degree of intraclutch variability in egg size. We also performed two food-supplementation experiments to investigate the proximate role of food supply during laying in determining egg size. Females with relatively abundant food and those in good body condition did not lay eggs that were more uniform in size than those laid by control females. This result is contrary to hypotheses that propose an adaptive explanation for intraclutch egg-size variation and also to ideas of energy depletion during laying. Patterns of egg size versus laying order were different between years, suggesting that females did not adaptively manipulate laying order and egg size within a clutch. The food-supplementation experiments showed that laying female kestrels probably depend on both stored energy reserves and on daily energy surpluses to form eggs. It appears that slight intraclutch variations in egg size occur in response to short-term food shortages during laying, but that these variations are probably nonadaptive. This is in marked contrast to interclutch (among females) variation in egg size, which we have shown varies significantly with food supply.

scholarly journals The Role of Proximate Determinants and Distal Variables On Recent Fertility in Dabat Health and Demographic Surveillance System Site, Northwest Ethiopia: A Mediation Analysis

2021 ◽  
Author(s):  
Nega Mihret Alazbih ◽  
Assefa Hailemariam Kaya ◽  
Mezgebu Yitayal Mengistu ◽  
Kassahun Alemu Gelaye
Keyword(s):  
Mediation Analysis ◽  
Fertility Decline ◽  
Northwest Ethiopia ◽  
Married Women ◽  
Fertility Rate ◽  
Age Group ◽  
Proximate Determinant ◽  
Number Of Children ◽  
Proximate Determinants

Abstract Background In Ethiopia, previous studies have explored the role of the proximate determinants for recent fertility decline at national and regional levels. However, none of these studies have examined the role of socioeconomic factors on the observed fertility decline through these proximate variables. This study aimed to estimate the effects of proximate determinants of fertility and the contribution of distal variables in recent fertility in Dabat Health and Demographic Surveillance Site, northwest Ethiopia. Methods A community based cross-sectional survey was carried out in 2020 among 1649 women of reproductive age group. Data were collected using structured and interviewer administered questionnaire. Generalized structural equation model was employed for the mediation analysis to estimate the relationships among distal and mediating variables with outcome variable, children ever born, simultaneously. A difference approach was used to test whether the effects of predictor variables were mediated. Results The Total Fertility Rate (TFR) for the three years preceding the survey was estimated at 3.4 children per woman. The Age Specific Fertility Rate (ASFR) in the study area reached its peak in the age group of 25–29 with 191 children per 1000 women. Among the proximate determinants, only marriage was a significant proximate determinant of recent fertility. The probability of having birth was more than fivefold higher among currently married women (IRR = 5.6 with a P-value = 0.000) than their unmarried counterparts. Age of women, occupation of women, household wealth status, ideal number of children, and experiencing child death had a significant total effect on recent fertility that were decomposed to direct and indirect or mediated effects of variables. Conclusion Marriage was the only proximate determinant that stood out as a significant mediated variable through which the distal variables affected fertility. Findings also clearly indicated that female participation in non-agricultural occupation affected the recent fertility. Hence, women's level of employment should be raised to increase their economic independence that will reduce the desirability of early marriage which in turn lower the number of children. In addition, the prevailing strategies on family planning programs should be improved to enhance the prevalence of contraceptive use among married women that will accelerate the current fertility transition.

Morphogenesis of a New Human Herpes-Type Virus Isolate (Sasha Virus)

1973 ◽  
Vol 31 ◽  
pp. 592-593
Author(s):  
R. F. Zeigel ◽  
W. Munyon
Keyword(s):  
Virus Isolate ◽  
Calf Serum ◽  
Uranyl Acetate ◽  
Human Herpes ◽  
Human Embryonic Lung ◽  
Human Herpes Virus ◽  
Intracytoplasmic Inclusions ◽  
Hel Cells ◽  
And Control

In continuing studies on the role of viruses in biochemical transformation, Dr. Munyon has succeeded in isolating a highly infectious human herpes virus. Fluids of buccal pustular lesions from Sasha Munyon (10 mo. old) uiere introduced into monolayer sheets of human embryonic lung (HEL) cell cultures propagated in Eagles’ medium containing 5% calf serum. After 18 hours the cells exhibited a dramatic C.P.E. (intranuclear vacuoles, peripheral patching of chromatin, intracytoplasmic inclusions). Control HEL cells failed to reflect similar changes. Infected and control HEL cells were scraped from plastic flasks at 18 hrs. of incubation and centrifuged at 1200 × g for 15 min. Resultant cell packs uiere fixed in Dalton's chrome osmium, and post-fixed in aqueous uranyl acetate. Figure 1 illustrates typical hexagonal herpes-type nucleocapsids within the intranuclear virogenic regions. The nucleocapsids are approximately 100 nm in diameter. Nuclear membrane “translocation” (budding) uias observed.

The role of copper ions in hydrogen peroxide bleaching: Their origin, removal, and effect on pulp quality

TAPPI Journal ◽  
2012 ◽  
Vol 11 (7) ◽  
pp. 37-46 ◽  
Author(s):  
PEDRO E.G. LOUREIRO ◽  
SANDRINE DUARTE ◽  
DMITRY V. EVTUGUIN ◽  
M. GRAÇA V.S. CARVALHO
Keyword(s):  
Hydrogen Peroxide ◽  
Copper Ions ◽  
Peroxide Bleaching ◽  
Metals Removal ◽  
Peroxide Decomposition ◽  
Equipment Corrosion ◽  
And Performance ◽  
And Control ◽  
Main Effects

This study puts particular emphasis on the role of copper ions in the performance of hydrogen peroxide bleaching (P-stage). Owing to their variable levels across the bleaching line due to washing filtrates, bleaching reagents, and equipment corrosion, these ions can play a major role in hydrogen peroxide decomposition and be detrimental to polysaccharide integrity. In this study, a Cu-contaminated D0(EOP)D1 prebleached pulp was subjected to an acidic washing (A-stage) or chelation (Q-stage) before the alkaline P-stage. The objective was to understand the isolated and combined role of copper ions in peroxide bleaching performance. By applying an experimental design, it was possible to identify the main effects of the pretreatment variables on the extent of metals removal and performance of the P-stage. The acid treatment was unsuccessful in terms of complete copper removal, magnesium preservation, and control of hydrogen peroxide consumption in the following P-stage. Increasing reaction temperature and time of the acidic A-stage improved the brightness stability of the D0(EOP)D1AP bleached pulp. The optimum conditions for chelation pretreatment to maximize the brightness gains obtained in the subsequent P-stage with the lowest peroxide consumption were 0.4% diethylenetriaminepentaacetic acid (DTPA), 80ºC, and 4.5 pH.

From Container to Claustrum: Projective Identification in Couples

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Tamara Feldman
Keyword(s):  
Psychological Health ◽  
Projective Identification ◽  
The Self ◽  
The Other ◽  
Intimate Partners ◽  
And Control ◽  
The Relationship ◽  
As If

This paper is a contribution to the growing literature on the role of projective identification in understanding couples' dynamics. Projective identification as a defence is well suited to couples, as intimate partners provide an ideal location to deposit unwanted parts of the self. This paper illustrates how projective identification functions differently depending on the psychological health of the couple. It elucidates how healthier couples use projective identification more as a form of communication, whereas disturbed couples are inclined to employ it to invade and control the other, as captured by Meltzer's concept of "intrusive identification". These different uses of projective identification affect couples' capacities to provide what Bion called "containment". In disturbed couples, partners serve as what Meltzer termed "claustrums" whereby projections are not contained, but imprisoned or entombed in the other. Applying the concept of claustrum helps illuminate common feelings these couples express, such as feeling suffocated, stifled, trapped, held hostage, or feeling as if the relationship is killing them. Finally, this paper presents treatment challenges in working with more disturbed couples.

The Estimation of prostate specific antigen (PSA) concentrations in patients with prostatitis by fully automated ELISA technique.

2020 ◽  
Vol 3 (11) ◽  
pp. 1100-1104
Author(s):  
Hussein Naeem Aldhaheri ◽  
Ihsan Edan AlSaimary ◽  
Murtadha Mohammed ALMusafer
Keyword(s):  
Personal Information ◽  
Receptor Gene ◽  
Specific Antigen ◽  
Gene Clusters ◽  
Control Group ◽  
P Value ◽  
Group Data ◽  
Elisa Technique ◽  
And Control

      The Aim of this study was to determine Immunogenetic expression of  Toll-like receptor gene clusters related to prostatitis, to give acknowledge about Role of TLR in prostatitis immunity in men from Basrah and Maysan provinces. A case–control study included 135 confirmed prostatitis patients And 50 persons as a control group. Data about age, marital status, working, infertility, family history and personal information like (Infection, Allergy, Steroid therapy, Residency, Smoking, Alcohol Drinking, Blood group, Body max index (BMI) and the clinical finding for all patients of Prostatitis were collected. This study shows the effect of PSA level in patients with prostatitis and control group, with P-value <0.0001 therefore the study shows a positive significant between elevated PSA levels and Prostatitis.

The Role of Archives on the Incorporation of the Former Kangwane Homeland to Mpumalanga Province

2018 ◽  
Vol 47 (2) ◽  
Author(s):  
Nkholedzeni Sidney Netshakhuma
Keyword(s):  
South Africa ◽  
Qualitative Methodology ◽  
Management Policy ◽  
Records Management ◽  
Record Keeping ◽  
Mpumalanga Province ◽  
Specific Objective ◽  
National Archives ◽  
And Control

This study was conceptualised in order to assess the strategies used to incorporate the homeland of KaNgwane into Mpumalanga province after the cessation of apartheid in 1994. The specific objective of the study was to investigate the compliance of records and archives with the National Archives and Records Service of South Africa Act (Act No 43 of 1996), during the incorporation of the homeland of KaNgwane into Mpumalanga. The study adopted a qualitative methodology through document analysis, interviews and observations. The key findings revealed that the archives of the former homeland of Kangwane were not aligned with the requirements of the National Archives and Records Service of South Africa Act (Act No.43 of 1996.) Institutions seem to lack experience when it comes to the challenges of storing records and implementing arrangement and control systems. The frequent lack of a records management policy and few to no staff with record-keeping and archival backgrounds was also a concern. A shortage of space to store records safely was also one of the major issues that the study uncovered. There appears to be no concerted effort to retain important historical records. Many records are stored in several different locations in government buildings.  I conclude that archives play an essential role to the nation as the institutional memory.

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