Plasma Thyroxine in the Sow During Pregnancy and Lactation and During Resumption of Ovarian Activity After Weaning

Total thyroxine in plasma was studied during pregnancy, lactation and during the post weaning period. The ovarian activity was monitored by progesterone determinations, and oestrous symptoms were recorded. In the two sows studied during pregnancy there was a distinct decrease in total thyroxine values in the last month of pregnancy, reaching a minimum about the time of farrowing. Total thyroxine values stayed low during lactation, but from about the time of weaning and during the following two weeks the concentrations increased rapidly. There was no difference in the thyroxine pattern in sows resuming ovarian activity within normal time (10 days) after weaning (72 sows) compared with sows with delayed resumption of ovarian activity (19 sows). The thyroxine level after weaning did not differ between sows with “silent 11631” and sows with overt oestrus. Primiparous and pluriparous sows had also similar thyroxine values after weaning. Sows weaned in January—June had a little higher thyroxine concentrations after weaning than sows weaned in July—December. There was a significant negative correlation between number of suckling piglets and thyroxine concentrations before weaning. Free thyroxine index was calculated in some selected samples. The results suggested that the changes observed in total thyroxine reflect changes in the free thyroxine concentrations.     

Plasma Constituents in the Sow

The concentrations in plasma of total protein, urea-N, Ca, Mg, Na and K and the activity of aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) in plasma were studied in 20 sows from one week before weaning until four weeks after weaning. Ten of the sows resumed ovarian activity within 10 days after weaning, while in the other 10 sows the resumption of ovarian activity was delayed. Plasma glucose was studied in 10 sows from one week before weaning until two weeks after weaning, five of these sows had delayed resumption of ovarian function. After weaning the concentration of total protein and the ALAT activity increased, while plasma glucose and Mg decreased. Concerning ASAT, Ca, Na and K no changes were observed. A transient increase in urea-N level took place after weaning in sows with prolonged weaning-to-ovulation period. In sows with normal weaning-to-ovulation period no change in urea-N was observed. This was the only difference in blood chemistry observed between sows with normal weaning-to-ovulation period and sows with prolonged weaning-to-ovulation period.     

Assessment of fraction of hypoxic cells in human tumor xenografts with necrotic regions by dynamic contrast-enhanced MRI

The potential usefulness of gadopentetate dimeglumine (Gd-DTPA)-based dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) for assessing hypoxia in tumors with significant necrosis was investigated. Small (100-350 mm(3)) and large (500-1000 mm(3)) D-12 and U-25 tumors were subjected to DCE-MRI, measurement of the fraction of necrotic tissue, and measurement of the fraction of radiobiologically hypoxic cells. Images of E.F (E is the initial extraction fraction of Gd-DTPA and F is perfusion) and lambda (lambda is proportional to extracellular volume fraction) were produced by subjecting the DCE-MRI data to Kety analysis. Necrotic tissue could be identified in lambda images but not in E.F images of the tumors. Most voxels in viable tissue showed lambda values of 0.15-0.70, whereas the lambda values of most voxels in necrotic tissue were either <0.15 or >0.70. The E.F and lambda frequency distributions of the viable tissue, but not the E.F and lambda frequency distributions of the whole tissue, were consistent with the observation that the four groups of tumors showed similar fractions of radiobiologically hypoxic cells. E.F and lambda images may thus provide useful information on the extent of hypoxia in tumors provided that voxels in necrotic tumor regions are identified and excluded from the images.     

Natural Resource Management, Paradigm Shifts, and the Decentralization Reform in Mali

The mainstream view in natural resource management in African drylands has been that local people are responsible for natural resource degradation. Today, alternative views or new paradigms are emerging in several fields. These new paradigms, which support decentralization of natural resource management, are discussed in relation to the ongoing decentralization process in Mali. During the colonial period, heavily centralized governments were installed in all the French colonies. This structure was maintained by Malian governments after independence. However, following the recent transition to democracy, a decentralizing reform is being implemented. It is presently not clear whether these reforms will lead to mere deconcentration, involving the redistribution of administrative responsibilities within the central government, or whether Mali is heading toward real decentralization, devolving decision making powers to local communities. The gestion de terroir approach, which may be a useful tool in achieving decentralization in farming communities, would, in pastoral areas, cause more damage than benefit.     

One Leg or Two? Food Security and Pastoralism in the Northern Sahel

Should pastoralists in dryland Africa diversify or specialize in their productive activities? To investigate this question, we analyze data from a consumption survey and two surveys of the nutritional status of children in addition to qualitative interviews comparing nomadic and sedentary population groups in the Gourma area in northern Mali. We show how the children of pastoralists seem to be better nourished than children of sedentary farmers and that the children of the sedentarized nomads seem to be the worst off. Based on these findings, we first argue that sedentary farming appears to be a poorer adaptation than nomadic pastoralism in arid environments such as the northern Sahel. Secondly, we argue that the diversification argument (better to stand on two legs than one) is flawed for mobile pastoralists in the northern Sahel because the logistical and organizational costs of combining different modes of livelihood are large and easily become insurmountable for a single household.     

Diverging phenological responses of Arctic seabirds to an earlier spring

The timing of annual events such as reproduction is a critical component of how free‐living organisms respond to ongoing climate change. This may be especially true in the Arctic, which is disproportionally impacted by climate warming. Here, we show that Arctic seabirds responded to climate change by moving the start of their reproduction earlier, coincident with an advancing onset of spring and that their response is phylogenetically and spatially structured. The phylogenetic signal is likely driven by seabird foraging behavior. Surface‐feeding species advanced their reproduction in the last 35 years while diving species showed remarkably stable breeding timing. The earlier reproduction for Arctic surface‐feeding birds was significant in the Pacific only, where spring advancement was most pronounced. In both the Atlantic and Pacific, seabirds with a long breeding season showed a greater response to the advancement of spring than seabirds with a short breeding season. Our results emphasize that spatial variation, phylogeny, and life history are important considerations in seabird phenological response to climate change and highlight the key role played by the species’ foraging behavior.     

Synesthesia and Migraine: Case Report

Background  

Synesthesia is, as visual migraine aura, a common and fascinating perceptual phenomenon. Here we present a unique case with synesthesias exclusively during visual migraine auras.