Welfare Reform and Food Stamp Caseload Dynamics

We use state-level panel data for federal fiscal years 1980–1998 to estimate the impacts of welfare reform and the business cycle on food stamp caseloads. The model we employ is a dynamic function of past caseloads, economic factors, AFDC and Food Stamp Program policies, political factors, AFDC caseload levels, and unobserved fixed and trending heterogeneity. Our results suggest that the robust economy has substantially influenced the recent decline in food stamp caseloads, but that the estimated aggregate effect of welfare reform is modest—we attribute around 45 percent of 1994–1998 decline to the macroeconomy and about 5 percent to welfare reform. We do find substantial heterogeneity in the impact of AFDC waiver policies. States with JOBS sanctions policies but not family cap or earnings disregard waivers can expect a larger long-run decline in caseloads than those states with all three policies. In addition, we do find some evidence, albeit weaker, that states with waivers for unemployed able-bodied adults without dependents can expect higher caseload levels than states without the waivers and that the Electronic Benefits Transfer program is leading to food stamp caseload declines. An important finding of this study is that modeling food stamp caseload dynamics has implications for the estimated effects of policy changes and economic factors—when dynamic models are employed, we observe substantially reduced welfare-reform effects but significantly increased effects of the macroeconomy on food stamp caseloads. These results are robust to models that permit the simultaneous determination of AFDC and food stamp caseloads.

Regional similarities in the distributions of well yield from crystalline rocks in Fennoscandia

Well yields from Precambrian and Palaeozoic bedrock in Norway, Sweden and Finland exhibit very similar and approximately log-normal distributions: all three data sets exhibit a median yield of 600–700 L hr-1, despite the differences in climate and lithology. This similarity is tentatively reflected on a larger geographical scale by a meta-analysis of the international data sets on crystalline rock aquifers from other recently glaciated areas (i.e., without a thick regolith of weathered rock). An heuristic treatment of the Fennoscandian data sets suggests that this median yield is consistent with the following bulk properties of shallow (to c. 70–80 m depth) crystalline bedrock: transmissivity of 0.56 ± 0.30 m2 d-1 (6.4 ± 3.4 x 10-6 m2 s-1) and hydraulic conductivity of around 1.1 (± 0.6) x 10-7 m s-1

Project for the analysis of technology transfer Quarterly report, 1 Oct. - 31 Dec. 1969

Analysis of Tech Brief-Technical Support Package progra

New Limits on the Polarized Anisotropy of the Cosmic Microwave Background at Subdegree Angular Scales

We update the limit from the 90 GHz PIQUE ground-based polarimeter on the magnitude of any polarized anisotropy of the cosmic microwave radiation. With a second year of data, we have now limited both Q and U on a ring of 1 degree radius. The window functions are broad: for E-mode polarization, the effective l is = 191 +143 -132. We find that the E-mode signal can be no greater than 8.4 microK (95% CL), assuming no B-mode polarization. Limits on a possible B-mode signal are also presented.Comment: 4 pages, 3 figures, submitted to Astrophysical Journal Letter

Confined Maxwell Field and Temperature Inversion Symmetry

We evaluate the Casimir vacuum energy at finite temperature associated with the Maxwell field confined by a perfectly conducting rectangular cavity and show that an extended version of the temperature inversion symmetry is present in this system

Hydrodynamic theory for a flexible profile vertical axis turbine

A novel vertical axis turbine with flexible profiles was designed and previously tested on-site in a river channel. The turbine design was based on initial simplified mathematical analyses and model testing done to optimize turbine interactions with the surrounding hydrodynamic environment. A study has been performed to evaluate several analytical models with respect to their complexity, accuracy, and computational time. The Cascade model was considered overall best suited for further analytical studies and optimizing the design of the flexible profile turbine. Herein, the original Cascade model was combined with improved dynamic stall effects, flow curvature effects, and profile pitching. After such improvements, the current model becomes comparable with those used for complex computational fluid dynamic analysis, but does not require significant computational time and expense. Hence, the model proposed in this study can be used for rapid assessment of field-and lab-based experiments and the design optimization process to improve turbine function and design in different environments.Новая вертикальная осевая турбина с гибкими профилями была разработана и предварительно протестирована непосредственно в русле реки. Дизайн турбины базировался на предварительном упрощенном математическом анализе и тестировании модели для оптимизации взаимодействия турбины с окружающей гидродинамической средой. Проведена оценка нескольких аналитических моделей с точки зрения их сложности, точности и расчетного времени. Наиболее подходящей для дальнейших аналитических исследований и оптимизации конструкции гибкого профиля турбины признана каскадная модель. В данном случае оригинальная каскадная модель сочеталась с улучшенными эффектами динамического срыва, кривизны потока, изменением угла профиля. После таких улучшений настоящая модель становится сравнимой с теми, что используются для комплексного расчетного анализа динамики потока, но не требует значительных расчетного времени и расходов. Таким образом, модель, предложенная в данном исследовании, может быть использована для быстрой оценки экспериментов в лабораторных условиях и условиях эксплуатации, а также процесса оптимизации дизайна для улучшения функции и конструкции турбины в различных окружающих средах.Нова вертикальна осьова турбіна з гнучкими профілями була розроблена і попередньо протестована безпосередньо в руслі річки. Дизайн турбіни базувався на попередньому спрощеному математичному аналізі та тестуванні моделі для оптимізації взаємодії турбіни з навколишнім гідродинамічним середовищем. Проведена оцінка декількох аналітичних моделей з точки зору їх складності , точності та розрахункового часу. Найбільш відповідною для подальших аналітичних досліджень та оптимізації конструкції гнучкого профілю турбіни визнана каскадна модель. У даному випадку оригінальна каскадна модель поєднувалася з поліпшеними ефектами динамічного зриву, кривизни потоку, зміною кута профілю. Після таких поліпшень теперішня модель стає порівнянною з тими, що використовуються для комплексного розрахункового аналізу динаміки потоку, але не вимагає значних розрахункового часу і витрат. Таким чином, модель, що запропонована в даному дослідженні, можна використовувати для швидкої оцінки експериментів у лабораторних умовах і умовах експлуатації, а також процесу оптимізації дизайну для поліпшення функції і конструкції турбіни в різних навколишніх середовищах

The Influence of Intermittent Hypoxia on Erythropoietin Levels in Older Adults

Few minutes of hypoxia exposure stabilizes hypoxia-inducible factors, resulting in erythropoietin (EPO) gene transcription and production. A brief intermittent hypoxia exposure increased EPO levels in young healthy adults, suggesting that a single session of intermittent hypoxia has the potential to increase oxygen-carrying capacity. PURPOSE: To determine the effect of a single session of intermittent hypoxia on serum EPO levels and hemoglobin mass among older adults. We hypothesized that a single session of intermittent hypoxia would raise serum EPO levels and lead to an increase in hemoglobin mass in older adults. METHODS: Seventeen participants (8 women, age: 54 ± 8 years, height: 177 ± 10 cm, weight: 76 ± 14 kg, BMI: 24 ± 4 kg/m2) were randomly assigned to an intermittent hypoxia group (IH, n=11) or an intermittent normoxia group (IN, n=6). Intermittent hypoxia consisted of eight 4-minute cycles at a targeted arterial oxygen saturation of 80% interspersed with normoxic cycles to resaturation. Air was made hypoxic by titrating nitrogen into the breathing circuit. Intermittent normoxia consisted of the same protocol, but nitrogen was not added to the breathing circuit. Pulmonary gas exchange, arterial oxygen saturation, and hemodynamics were continuously measured throughout both protocols. EPO levels were measured before and 4.5 hours after the beginning of each protocol. Hemoglobin mass was assessed via carbon monoxide rebreathing the day before and seven days following intermittent hypoxia or normoxia. RESULTS: Intermittent hypoxia lowered arterial oxygen saturation (­­98 ±­ 1 to 82 ± 3 %, p\u3c0.01), which resulted in a lower fraction of inspired oxygen (20.8 ±­ 0.1 to 10.9 ± 1.0 %, p\u3c0.01). There was no significant change in EPO levels in either condition (IH:10.4 ±­ 2.9 to 13.3 ± 4.2; IN: 5.6 ±­ 2.4 to 6.5 ± 2.9 mU/ml, main effect for time p=0.12). Similarly, there was no change in hemoglobin mass in response to both conditions (IH: 752 ±­ 189 to 754 ± 189; IN: 858 ± 177 to 879 ± 157 g, main effect for time p=0.87). Intermittent hypoxia did not affect mean arterial pressure (87 ± 15 to 88 ± 14 mmHg, p=0.18) or cardiac output (5.5 ± 1.5 to 5.7 ± 1.5 L/min, p=0.22), but increased heart rate (62 ± 9 to 68 ± 9 bpm, p\u3c0.01). CONCLUSION: A single session of eight 4-minute cycles of intermittent hypoxia did not increase serum EPO levels in older adults

A Limit on the Polarized Anisotropy of the Cosmic Microwave Background at Subdegree Angular Scales

A ground-based polarimeter, PIQUE, operating at 90 GHz has set a new limit on the magnitude of any polarized anisotropy in the cosmic microwave background. The combination of the scan strategy and full width half maximum beam of 0.235 degrees gives broad window functions with average multipoles, l = 211+294-146 and l = 212+229-135 for the E- and B-mode window functions, respectively. A joint likelihood analysis yields simultaneous 95% confidence level flat band power limits of 14 and 13 microkelvin on the amplitudes of the E- and B-mode angular power spectra, respectively. Assuming no B-modes, a 95% confidence limit of 10 microkelvin is placed on the amplitude of the E-mode angular power spectrum alone.Comment: 4 pages, 3 figures, submitted to Astrophysical Journal Letter

Breaking the Redshift Deadlock - I: Constraining the star formation history of galaxies with sub-millimetre photometric redshifts

Future extragalactic sub-millimetre and millimetre surveys have the potential to provide a sensitive census of the level of obscured star formation in galaxies at all redshifts. While in general there is good agreement between the source counts from existing SCUBA (850um) and MAMBO (1.25mm) surveys of different depths and areas, it remains difficult to determine the redshift distribution and bolometric luminosities of the sub-millimetre and millimetre galaxy population. This is principally due to the ambiguity in identifying an individual sub-millimetre source with its optical, IR or radio counterpart which, in turn, prevents a confident measurement of the spectroscopic redshift. Additionally, the lack of data measuring the rest-frame FIR spectral peak of the sub-millimetre galaxies gives rise to poor constraints on their rest-frame FIR luminosities and star formation rates. In this paper we describe Monte-Carlo simulations of ground-based, balloon-borne and satellite sub-millimetre surveys that demonstrate how the rest-frame FIR-sub-millimetre spectral energy distributions (250-850um) can be used to derive photometric redshifts with an r.m.s accuracy of +/- 0.4 over the range 0 < z < 6. This opportunity to break the redshift deadlock will provide an estimate of the global star formation history for luminous optically-obscured galaxies [L(FIR) > 3 x 10^12 Lsun] with an accuracy of 20 per cent.Comment: 14 pages, 22 figures, submitted to MNRAS, replaced with accepted versio