Uneven Change Research Articles

The cupping of lumber depending onchangeoftheir moistureand geometric characteristics

Laminated panels are common among structural elements for the production of a variety of wood products. Most studies of laminated structures are limited to the analysis of their physical and mechanical characteristics. In the case of using laminated panelsas the facade surfaces of joinery and furniture, the importance of their aesthetics is also important. The quality of the laminated structures is conditioned by the properties of its individual sections, so it is important to take into account the properties of these sections for the rational choice of the scheme for the formation of the laminated structure and to predict its quality. The main reasons for the possible change in the shape of the surfaces of the laminated structures are described. Drying and swelling lead to a change in the size and shape of both parts and products of wood and lumber used for their manufacturing. The warpingof lumber is a pronounced defect. The main causes of the lumber warpingare the anisotropy of the properties of the wood and the unevenness of its structure, as well as the uneven change in moisture in different structural directions. The lumber, depending on their location in the log, has unequal resistance to the transverse cup warping. When calculating moisturedeformations, the concept of relative deformation of drying is used. Quantitative characteristics of wood drying are the corresponding coefficients of drying characterizing the change in geometric dimensions. If the drying of the layers of the board is not equal, then such boards will have a transverse cup warping. In order to solve the problem of rational choice of the formation scheme of laminated panel structures and predicting their quality even before gluing, the mathematical model for the theoretical study of the shape change of lumber was developed. Obtained engineering formulas for calculating the coefficients of wood drying show that the form change of lumber depends mainly on its size, moisture and location in the log. To determine the magnitude of the shrinkage coefficients of the lumber layers, it is advisable to use the shrinkagecoefficients in the radial and tangential directions.

Distal pressure monitoring and titration with percent balloon volume: feasible management of partial resuscitative endovascular balloon occlusion of the aorta (P-REBOA).

Resuscitative endovascular balloon occlusion of the aorta (REBOA) increases proximal arterial pressure, but may also induce life-threatening distal ischemia. Partial REBOA (P-REBOA) is thought to mitigate distal ischemia during aortic occlusion. However, feasible indicators of the degree of P-REBOA remain inconsistent. We hypothesised percent balloon volume could be a substitute for pressure measurements of gradients during P- REBOA. This study aimed to compare balloon volume and arterial pressure gradient, and analysed with intra-balloon pressure and balloon shape. Proximal (carotid) and distal (femoral) arterial pressures were recorded and a 7-Fr REBOA catheter was placed in four swine. Total REBOA was defined as a cessation of distal pulse pressure and maximum balloon volume was documented. The balloon volume was titrated by 20% increments of maximum capacity to adjust the degree of P-REBOA. The distal/proximal arterial pressure gradient and the intra-balloon pressures were also recorded. The changes in shape and the cross-sectional area of the balloon were evaluated with computed tomography (CT) images. The proximal mean arterial pressure (MAP) plateaued after 60% balloon volume; meanwhile, distal pulse pressure was still left. The balloon pressure was traced with proximal MAP before contact with aortic wall. The balloon shape changed unevenly from "cone" to "spindle" shape, although the balloon cross-sectional area of the mid-segment linearly increased. Monitoring distal pressure and titrating percent balloon volume is feasible to manage P-REBOA. In this experiment, 60% balloon volume was enough inflation to elevate central pressure allowing distal perfusion. The intra-balloon pressure was not reliable due to the strong influence of proximal MAP and uneven change of the balloon shape.

Sectoral determinants of sub-federal budget tax revenues: Russian case study

Research background: The research is based on the assumption that the sectoral structure of economy has a significant impact on the level and dynamics of sub-federal budget tax revenues. It distinguishes the following sectoral determinants of tax revenues in regions: the levels of tax return and tax absorption, inflation and economic growth in various economic activities.
 Purpose of the article: We aimed at assessment of contribution of economic activities and their determinants to the increase in tax revenues of sub-federal budgets of the Russian Federation in 2011?2015 compared to 2006?2010.
 Methods: Development of a four-factor additive-multiplicative model of the tax revenue formation in regions, application of the proportional and logarithm methods of factor analysis to assessment of contribution of various activities and their determinants to increase in tax revenues of sub-federal budgets, evaluation of inter-regional inequality of tax revenues growth based on the weighted coefficient of variation, and decomposition of this inequality using the A. Shorrocks technique.
 Findings & Value added: We identified activities that made the largest contribution to the increase in tax revenues of the Russian sub-federal budgets. We found that the inflation factor had a predominant positive effect on the growth of tax revenues, while the contribution of the economic growth factor was 4 times less; however, the situation in various activities differed significantly. Generally, changes of sectoral levels of tax return and tax absorption influenced negatively the regional tax revenues. In addition, they moved in opposite direction in the regions. Ultimately, the uneven change in tax returns and price levels in the mining and manufacturing activities of Russian regions made the greatest contribution to inter-regional inequality of the growth of sub-federal budgets tax revenues.

Uneven acute non-alcoholic fatty change of the liver after percutaneous transhepatic portal vein embolization in a patient with hilar cholangiocarcinoma \u2013 a case report

BackgroundPortal vein embolization is essential for patients with biliary cancer who undergo extended hepatectomy to induce hypertrophy of the future remnant liver. Over 830 patients have undergone the portal vein embolization at our institution since 1990. Non-alcoholic fatty liver disease is an entity of hepatic disease characterized by fat deposition in hepatocytes. It has a higher prevalence among persons with morbid obesity, type 2 diabetes, and hyperlipidemia. Neither the mechanism of hepatic hypertrophy after portal vein embolization nor the pathophysiology of non-alcoholic fatty liver disease has been fully elucidated. Some researchers integrated the evident insults leading to progression of fatty liver disease into the multiple-hit hypothesis. Among these recognized insults, the change of hemodynamic status of the liver was never mentioned.Case presentationWe present the case of a woman with perihilar cholangiocarcinoma who received endoscopic biliary drainage and presented to our institute for surgical consultation. A left trisectionectomy with caudate lobectomy and extrahepatic bile duct resection was indicated for curative treatment. To safely undergo left trisectionectomy, she underwent selective portal vein embolization of the liver, in which uneven acute fatty change subsequently developed. The undrained left medial sector of the liver with dilated biliary tracts was spared the fatty change. The patient underwent planned surgery without any major complications 6 weeks after the event and has since resumed a normal life. The discrepancies in fatty deposition in the different sectors of the liver were confirmed by pathologic interpretations.ConclusionThis is the first report of acute fatty change of the liver after portal vein embolization. The sparing of the undrained medial sector is unique and extraordinary. The images and pathologic interpretations presented in this report may inspire further research on how the change of hepatic total inflow after portal vein embolization can be one of the insults leading to non-alcoholic fatty liver disease/ change.

A Case Report and Literature Review of Hepatic Follicular Dendritic Cell Sarcoma

To investigate the clinical manifestation, imaging features, pathological characteristics, and diagnosis of hepatic follicular dentritic cell sarcoma, a case report combined with literature review was introduced. A large single mass in liver was showed in CT scan. Enhanced CT showed obvious uneven change of liver neoplasm during the arterial phase and the portal vein phase with tortuous disorganized blood vessels. Immumohistochemical staining of CD21, CD23 and EBER was positive. HFDCS is extremely rare. Except for pathologicaldiagnosis by liver biopsy, its preoperative diagnosis rate is extremely low. Its diagnosis is based on the histopathology and immumohistochemistry. HFDCS was first reported by Shek in 1996, and often occurred in women aged 19 - 82 years (with an average age of 46.7 years). Its main clinical manifestations were abdominal pain, abdominal distention, weight loss, anemia, fever, etc. Some patients were asymptomatic.

Aging Human Hematopoietic Stem Cells Manifest Massive Epigenetic Reprogramming and Altered Gene Splicing of Key Hematopoietic Gene Sets

Aging leads to impairment of hematopoietic stem cell (HSC) function with decreased self-renewal, imbalanced differentiation potential and an increased risk to develop myeloid malignancies. These malignancies are associated with epigenetic deregulation, which contributes to pathogenesis. Notably, studies in murine models have revealed epigenetic changes in aged HSC. However, it is unknown if this occurs in normal human HSC aging and whether it may contribute to HSC dysfunction. Therefore, we performed comprehensive epigenomic and transcriptional profiling in primary human HSC (Lin-, CD34+, CD38-) isolated from young (18-30 yo), mid (45-55 yo) and old (65-75 yo) healthy donors. Using a micro-ChIP-seq protocol we profiled H3K4me1, H3K4me3, H3K27me3 and H3K27ac in 4-7 donors per age group, as well as genome-wide DNA methylation (5mC), hydroxymethylation (5hmC) and RNA-seq.Analysis of enhancer-associated marks revealed that with age there is marked reduction in both H3K4me1 and H3K27ac (20,783 and 15,625 peaks lost, respectively; log10likelihood ratio >3). Gene ontology analysis of these lost peaks revealed their association with genes involved in hematopoiesis and, RNA splicing and chromatin organization, respectively (ChIPenrich, FDR<0.05). In addition, regions depleted in H3K4me1 are enriched for PU.1, FLI1, ETS, and CTCF binding sites (Homer, q<0.00001). We next asked if aging results in specific remodeling of poised (H3K4me1>H3K4me3, H3K27ac-) and active (H3K4me1>H3K4me3, H3K27ac+) enhancers. We found age-related loss of H3K4me1 enrichment at 10,696 poised enhancers, which are associated with hematopoiesis and T- and B-cell receptor signaling (FDR<0.05). We also identified 17,242 active enhancers in young HSC, 7,057 of which are depleted in old HSC. This loss of active enhancers targets genes associated with hematopoiesis, immune signaling and myeloid malignancies (FDR<0.05). Next we analyzed the impact of aging on promoter-associated marks, H3K4me3 and H3K27me3. Remarkably, while aging leads to loss of 22,689 H3K4me3 peaks, only 1,339 H3K27me3 peaks are lost. Loss of H3K4me3 targets genes involved in inflammatory response, development and WNT signaling (FDR<0.05). Given this uneven change in H3K4me3/H3K27me3 with aging, we hypothesized this may correlate with changes in bivalently marked promoters, which regulate key developmental genes. Out of 3,947 bivalent promoters in young HSC, 842 are lost in aged HSC. This loss of bivalency affects genes involved in WNT, Cadherin and Hedgehog signaling pathways (FDR<0.05). Next we analyzed changes in cytosine modifications. We observe widespread gain of 5hmC (n=14,554 differentially hydroxymethylated regions [DHMR]; FDR <0.005), with specific enrichment at introns and exons (p<2.2e-16), as well as enrichment for GATA and KLF binding sites (Homer, q<0.00001). These DHMR target genes involved in hematopoiesis, proteins regulated by alternative splicing, and pathways associated with cancer (FDR<0.05). In contrast, much more subtle changes are found in 5mC with HSC aging, with only 529 differentially methylated regions (q-value <0.05, meth.diff >20%). However, these subtle changes also target genes associated with cadherin and WNT signaling. Finally, RNA-seq analysis revealed that this age-associated epigenetic reprogramming is accompanied by an overall trend to gene downregulation. Amongst the genes most affected are the nuclear lamin gene LMNA (mutated in progeria syndrome), splicing factors SRSF7 and U2AF1 and, the transcription factors KLF3/6 and HIF1α (FDR <0.05, fold change >1.5). Notably, changes in expression also include significant differential exon usage, which may be mediated by DHMR at intron-exon boundaries: 575 genes show altered exon usage (FDR <0.05, fold change>1.5) including LMNA and the epigenetic modifiers BRD9, CITED2, KDM6A and SETD6.In summary, we have completed the first comprehensive epigenomic profiling of aging in human HSC. Our findings show massive epigenetic remodeling in aged HSC, consisting of loss of activating histone marks primarily targeting enhancers and bivalent promoters at genes involved in hematopoiesis and developmental pathways. Cytosine modifications show widespread changes in 5hmC, targeting intron-exon boundaries. Globally, this epigenetic reprogramming results in overall gene downregulation and altered splicing of genes important for HSC regulation. DisclosuresNo relevant conflicts of interest to declare.

Morphological and functional aspects of neurosecretory process in hypothalamic nuclei in heart failure

V.G. Papkov Hypothalamus studied in 18 men who died from injuries, acute coronary insufficiency and congestive heart failure. In the supraoptic (SOY) and paraventricular (PVN) nuclei determined percentage neurocyte that are in various phases of neurosecretory cycle. Calculated the index of the functional activity of the nuclei. Revealed an uneven change in the ratio neurocyte that are in various phases of neurosecretion and index decreased functional activity of SOY in various forms of heart failure. The index of the functional activity of the PVN in acute coronary insufficiency remains on the "control" value. The observed changes are regarded as a morphological indicator of the regulatory function of the hypothalamus.

HYDRODYNAMICS OF PLATE COLUMN FOR ENZYMATIC REACTIONS OF OIL

This work describes the hydrodynamics of a plate column of 5 cm inner diameter and 2.75 m height, operated in a semi-batch manner using an oil-water system especially important for enzymatic catalyzed reactions. The parameters such as dispersed phase superficial velocity, plate orifice size, number of nozzles, nozzle size and plate spacing, affecting the dispersed phase hold up, were investigated. It was observed that the orifice plate produced an uneven change in drop diameter and hence nozzles were used to study the hydrodynamics. The total and dynamic hold ups determined were increased with an increase in dispersed phase superficial velocity, while decreased with an increase in a nozzle size. The total hold up decreased, while dynamic hold up slightly increased with an increase in plate spacing. Correlations obtained are found to be appropriate for the estimation of the total hold up and dynamic hold up.

Impacts of land use change and climate variability on green and blue water resources in the Weihe River Basin of northwest China

BackgroundLand use change and climate variability influence water resources availability and separation of these influences are important for water resources management. MethodsSWAT model and the Mann–Kendall method were used in this study which investigated the spatiotemporal variations of blue and green water resources under different land use change, agricultural irrigation expansion and climate variability scenarios during the 1980s–2000s for the Weihe River Basin. ResultsFarmland area decreased by 1.4% and woodland, grassland, and construction land area increased by 0.6%, 0.2%, and 0.6%, respectively. The combined impact of land use change, agricultural irrigation expansion and climate variation decreased the blue water flow, green water flow, and green water storage by 21.62mmyear−1, 35.01mmyear−1 and 28.07mmyear−1, respectively. Climate variability decreased the blue/green water flow and green water storage, land use change decreased the blue water and green water flow while it increased the green water storage, irrigation expansion decreased the blue water flow while it increased the green water flow/storage. The spatial distribution showed an uneven change in the Weihe River Basin. Together, we suggested that the variability of water resources availability in the Weihe River Basin was mainly attributed to climate variability, while land use change plays a key role in the sub-basins which experienced dramatic changes in land use.

Smart-Horizontal-Well Drilling and Completion for Thin-Oil-Rim Reservoirs in Malaysia

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper IPTC 17753, “Smart Horizontal-Well Drilling and Completion for Effective Development of Thin-Oil-Rim Reservoirs in Malaysia,” by Keng Seng Chan, Rahim Masoudi, Hooman Karkooti, Ridzuan Shaedin, and Mohamad B. Othman, Petronas, prepared for the 2014 International Petroleum Technology Conference, Kuala Lumpur, 10–12 December. The paper has not been peer reviewed. For thin-oil-rim reservoirs, well placement, type and path, and well-completion methods, should be evaluated with close integration of key reservoir- and production-engineering considerations. This process involves maximizing reservoir-fluid contact and drainage, optimizing well productivity, and optimizing the production profile along the wellbore. Field-implementation cases in Malaysia have demonstrated that this integrated approach to horizontal wells can significantly minimize well count, enhance well performance, and improve ultimate recovery per well in thin-oil-rim reservoirs with varying reservoir complexities and uncertainties. Introduction Development of oil-rim reservoirs in Malaysia has improved progressively through a series of reservoir-engineering studies and successful field implementations. Although typical oil-rim reservoirs are characteristically wedged between a gas cap and an underlying aquifer, they can be structurally complicated by faults and flow boundaries, featuring various dips and saddles. Oil-rim reservoirs of various sand thickness can also be stacked and compartmentalized. Aquifer support can vary from one reservoir sector to another, resulting in uneven pressure depletion and fluid-contact change. Fig. 1 shows such a vast oil-rim reservoir in peninsular Malaysia. Early oil-rim-reservoir field-development strategy consisted mainly of drilling a large number of vertical or low-angle wells. Wells are completed with multiple strings in order to produce separately from various different but stacked sands with significantly large pressure differences. Well life can be short, producing at high water cut and high gas/ oil ratio (GOR) because of the wells having partial penetration at high pressure drawdown. In such a well-development strategy, idle-well counts increase dramatically. Currently, active wells in some key oil-rim reservoirs are far less than 50% of the inventory. Field oil recovery remains low even after 25 years of continuous production. Force Balance in Thin-Oil-Rim Reservoirs There are several drive mechanisms dominant in oil-rim reservoirs—namely, gas-cap expansion, drive, viscous withdrawal, and gravity balance, in addition to solution-gas-expansion drive. Producing-gas reinjection; controlled pressure drawdown at wells in different reservoir sectors on the basis of varying aquifer strength and sand-layer dip angle; and the placement, spacing, and completion of the wells could all affect the balance of these drives. The art of this balance is to keep the oil rim in place, avoiding pronounced migration. A subtle balance of forces can keep the oil rim in place for many years with minimum pressure decline and more-even fluid withdrawal across the reservoir (Fig. 2). Even though oil-rim reservoirs could have a huge underlying aquifer, the bottomwater support may not be adequate in some oil-rim-reservoir sectors. Some oil-rim reservoirs in Malaysia have observed a significant pressure decline. Water and gas injection should also be implemented, if not for the whole field then selectively in some regions, in order to preserve force balance, minimize oil migration, and improve oil recovery. Injection strategies and methods include periphery or fencing, updip water injection, and downdip gas injection.

Violent enclosures, violated livelihoods: environmental and military territoriality in a Philippine frontier

The political geography of environmental governance can overlap and converge with uneven agrarian change in forest frontiers subject to violent enclosures. When the governance of conservation territories converges with and reinforces enclosures, spaces can be controlled with authority and violence that places livelihoods at greater risk in the context of uneven agrarian political economies – the outcomes of which reflect ‘violent enclosures’. This paper examines how indigenous resource users negotiate the discursive and material impact of environmental governance converging with militarized-insurgent spaces as overlapping enclosures in a protected area on Palawan Island, the Philippines. Drawing on local experiences, we examine how the livelihood vulnerability arising in the local political economy is exacerbated by access and use constraints from the overlapping enclosures of environmental and military governance in the buffer zone of Puerto Princesa Subterranean River National Park. We argue that the seemingly less governable forest frontiers of protected areas are often the poorest, highly politicized and contested spaces of political and ecological refuge. Here, scarce forest resources are managed closely, and recalcitrant groups seek refuge as military powers frame, conflate and manage local behaviour as criminal and dangerous, merging conservation and military interventions as coercive governance. We conclude that only by critically engaging how governance processes and enclosures converge to yield structural and discursive violence – and by making this apparent to policy makers – will indigenous peoples successfully negotiate the double bind of violent enclosures in frontiers.

Earlier Arctic springs cause phenological mismatch in long-distance migrants

An uneven change in climate across the Northern Hemisphere might severely affect the phenology of migrating animals, and especially long-distance migrating birds relying on local climatic cues to regulate the timing of migration. We examine the forward displacement of spring in both staging areas and breeding grounds of one such population, the East Atlantic light-bellied brent goose Branta bernicla hrota, and evaluate to what extent their migration has made a proportional response. On the breeding grounds in Svalbard the onset of spring advanced 2 weeks during the 24-year period, whereas no significant trend was found in the temperate staging areas. The timing of migration was constant throughout the study period, mirroring the static climatic conditions in the spring staging areas. These findings indicate a global warming-induced phenological mismatch in light-bellied brent geese, as these might arrive on their breeding grounds well beyond optimal breeding conditions. Our data indicated that productivity was negatively influenced by phenological delay and positively influenced by prolonged snow cover. We argue that both these effects might be representative of a negative influence of the growing phenological mismatch, because years with later thaw might partly offset the effects of increasingly earlier Svalbard springs. During the study period reproduction fell below annual mortality, and the population declined in recent years. The wider implications of these findings may extend to many migrating species, and highlight the urgent need to clarify how global change may influence cues and the associated timing of important life history activities.

Adapted Non-Circular Soft Turning of Bearing rings–Impact of Process Machine Interactions on Compensation Potential

Distortion considerably influences manufacturing costs, especially if thin-walled parts are machined. To ensure a flexible economical machining, novel processes have to be developed to control distortion within the process chain. Then, reworking by straightening during quenching or by costly hard processing can be kept to a minimum. The fundamental concept of ‘Distortion Engineering’ is based on the inverse application of identified distortion potential to compensate geometric deviations. In the case of thin-walled bearing rings the distortion is related to both, deviation of the wall thickness and the shape. These deviations originate mainly from an inhomogeneous material removal and uneven residual stress state in the workpieces subsurface caused by deformations due to clamping forces during the soft-turning. An adapted non-circular finishing cut can counteract the distortion. Previous work showed that the adaption of depth of cut depending on assessed geometric irregularities reduces deviations by at least two-third compared to non-compensated cutting. Compensation to zero deviation needs a deeper understanding; hence disturbances during the compensation cuts are investigated within this paper. An uneven change of subsurface residual stress state has a retro-active effect on the workpieces’ shape. Experimental results illustrate that the mechanical process loads are alternating with oscillation of the depth of cut. However, only an impact of adapted cutting on residual stresses perpendicular to the cutting direction (axial stresses) was detected. So far, it can be concluded that adapted cutting not leads to an unexpected change of out-of-roundness during subsequent heat treatment. Additionally, the results revealed that the compensation potential is highly affected by a change of workpieces’ deformation due to material removal during one longitudinal cut.

Downstream Effects of a Hybrid Forum: The Case of the Site C Hydroelectric Dam in British Columbia, Canada

Attempting to scale up the deployment of renewable energy technology has come with considerable controversy and opposition. Research exploring this opposition has highlighted the importance of project control and decision-making structures, including public engagement and consultation. This article contributes to the discussion by considering how participatory processes might have varying effects across space and time. Combining the concept of hybrid forums with spatial theories of change, it explores participatory processes and how they can result in uneven change in sociotechnical networks. It applies this theoretical framing to one hydroelectric project in northeastern British Columbia, to show how lessons learned from this project, and, from the legacy of hydroelectricity more generally, are not consistent throughout the province and how attempts to manage these differences have led to further conflict and opposition.

A Waste of Space: Bodies, Time and Urban Renewal

A Waste of Space: Bodies, Time and Urban Renewal

Use of Optical Imaging/Image Analysis System for the Quantitative Analysis of Surface Changes Induced by Outdoor Weathering on Sealants

Abstract Six sealant samples that had been weathered outdoors for 6.8 years in Japan were evaluated using an Optical Imaging/Image Analysis System, Atlas VIEEW™. The specimens were first visually evaluated with aesthetic ratings assigned. These ratings were then used as the reference for the optical image analysis. Image analysis was carried out on sealant images taken under optimized diffuse illumination at a constant illuminance. Two sets of images were captured per specimen, first the weathered surface for deterioration evaluation, and second the unweathered surface as a control (reference) image. Four distinct surface defects are quantifiable in the samples. These are cracking (crazing), visual color change, spatial uniformity of deterioration (due to dirt pick-up and uneven color change, or both), and overall surface texture. Chalking and dirt pick up, as rated visually prior to this evaluation, could not be accurately assessed with the digital imaging technique. The analysis shows that surface cracking and crazing generally can be well characterized using the automated VIEEW™ system. Judging color changes visually is problematic, since cracking and crazing interferes with color judgment. Further investigations are needed to develop an automated surface characterization method for sealants.

The Effects of Sustained Hyperventilation on Regional Cerebral Blood Volume in Thiopental-Anesthetized Rats

Sustained hyperventilation has a time-limited effect on cerebrovascular dynamics. We investigated whether this effect was similar among brain regions by measuring regional cerebral blood volume (CBV) with steady-state susceptibility contrast magnetic resonance imaging during 3 h of hyperventilation. Regional CBV was determined in nine thiopental-anesthetized, mechanically-ventilated rats every 30 min in the dorsoparietal neocortex, the corpus striatum, and the cerebellum. The corpus striatum was the only brain region showing a stable reduction in CBV during the hypocapnic episode (PaCO(2), 24 +/- 3 mm Hg). In contrast, neocortex and, to a lesser extent, cerebellum exhibited a progressive return toward normal values despite continued hypocapnia. No evidence of a rebound in CBV was found on return to normal ventilation in the three brain regions. We conclude that sustained hyperventilation can lead to an uneven change in the reduction of CBV, possibly because of differences of brain vessels in their sensitivity to extracellular pH. Our results in neocortex confirm the transient effect of sustained hyperventilation on cerebral hemodynamics. Sustained hyperventilation has a transient effect in decreasing cerebral blood volume (CBV). Using susceptibility contrast magnetic resonance imaging in thiopental-anesthetized rats, we found differences between brain regions in their transient CBV response to sustained hyperventilation.

A process tracing plausibility probe of uneven democratization's effects on cooperative dyads: The case of Zambia and Zimbabwe 1980–1993

In this article we conduct a plausibility probe of the hypothesis that uneven democratization decreases cooperation within primarily cooperative dyads. This hypothesis is derived from a combination of Remmer's theory of democratization and international cooperation with democratic peace theory. The case of cooperation and conflict between two small powers, Zambia and Zimbabwe, from the latter's independence in 1980 to 1993 fits Eckstein's criteria for a useful plausibility probe. In addition to overall, bilateral and regional interactions between the two countries, we examine relations in the political, economic, strategic, and physical environment issue areas. Methodologically, we combine time series analysis of events coded in the COPDAB format and interviews with policy makers. We find that, although net cooperation between the two countries remained positive during the entire 1980–1993 period, it decreased significantly overall and in economic issues after the beginning of the Zambian democratic transition in June 1990. Our data allow us to trace the process involved in this decline in net cooperation, ruling out some alternative explanations but not concurrent Structural Adjustment Programs (SAPs), and showing how even slightly uneven democratization was an important cause because it decreased similarity and trust, while not decreasing transparency, and increased uncertainty and thus nationalist responses. We conclude that this plausibility probe justifies further systematic research on the effects of uneven democratization on cooperative dyads to test our hypothesis on cases with and without SAPs, and suggests the utility of further probes of the effects of different types of uneven change on various types of dyads.

Inside the black box: Dimensions of gender, generation and scale in the Australian rural restructuring process

Using a case study of the South Australian farm crisis of the late 1980s and early 1990s, the article seeks to sympathetically engage with Whatmore's [Whatmore, 1991a; Farming Women: Gender, Work and Family Enterprise, Macmillan, London; Whatmore, 1991b. Journal of Rural Studies, 7(1/2), 71–76] feminist reconstruction of simple commodity production (SCP). It explores the extent to which Whatmore's reformulation of the SCP concept offers a scale- and agency-sensitive framework through which contemporary processes of agrarian change, including changing gender roles in many facets of rural and farming life, can be seen. Using Whatmore's adaptation of Connell's (Connell, 1987, Gender and Power: Society, The Person and Sexual Politics, Allen and Unwin, Sydney) ‘gender order’ and ‘gender regime’ to examine the survival strategies of Kangaroo Island farm families from 1984 to 1993, the article reveals that while Island farm women have played fundamental and diverse roles in the defence of the family farm and the farm family through their on- and off-farm and household labour, farm men's roles have changed little. Nevertheless, the article does find that the established gender order is undergoing gradual and uneven change as a familial ideology - where the maintenance of family living standards is considered more important than the preservation of the family's ties with the land - assumes importance in some young families' adjustment responses. In summary, the article finds that Whatmore's ‘domestic political economy’ provides an important advance in understanding how farm families, and individual farm women and men, negotiate global, national, regional and local pressures for economic and social change.

Effects of Nitrous Oxide on Human Regional Cerebral Blood Flow and Isolated Pial Arteries

Results from previous studies on the effect of nitrous oxide (N2O) on the cerebral circulation are conflicting. Early reports claim N2O to have no effect whereas recent findings demonstrate a cerebral cortical vasodilatation during N2O inhalation, but the regional cerebral blood flow (CBF) in the subcortical structures is unknown. Regional CBF was measured three-dimensionally with single photon emission computer-aided tomography after injection of xenon 133 in 8 spontaneously breathing men (mean age 29.6 yr) during normocapnia and hypocapnia with and without inhalation of 50% N2O. 8 isolated human pial arterial segments were mounted in organ baths. The segments were contracted with prostaglandin F2 alpha and subjected to 30% oxygen and 5.6% carbon dioxide in nitrogen or N2O. Normocapnic young men had a global CBF of 55 +/- 4 ml.100 g-1.min-1. Decreasing end-tidal CO2 tension by 1.3 kPa (9.3 mmHg) reduced CBF uniformly, with a decrease in global CBF to 45 +/- 2 ml.100 g-1.min-1 (P < 0.0001). During normocapnia, inhalation of 50% N2O increased mean CBF to 67 +/- 7 ml.100 g-1.min-1 (P < 0.0001). Inhalation of 50% N2O during hypocapnia increased mean CBF to 63 +/- 5 ml.100 g-1.min-1 (P < 0.0001). During N2O inhalation there was no significant difference in mean CBF between normo- and hypocapnia. However, during hypocapnia, but not during normocapnia, N2O inhalation significantly changed the distribution of regional CBF (P < 0.0001). Compared with hypocapnia without N2O, flow increased through the frontal (143%), parietal (140%) and temporal (133%) regions as well as through insula (151%), basal ganglia (145%) and thalamus (133%). In isolated human pial arteries, addition of N2O changed neither basal tension, nor the contraction elicited by prostaglandin F2 alpha. Inhalation of 50% N2O increased global CBF mainly by augmenting flow in frontal brain structures. In contrast, changes in carbon dioxide without N2O affected CBF uniformly in the brain. The uneven change in distribution of the CBF when N2O was added during hypocapnia, the reduced carbon dioxide response, and the lack of effect of N2O on isolated human pial arteries suggest that N2O may increase metabolism in selected brain areas.