Temperature-sensitive Tien Shan tree ring chronologies show multi-centennial growth trends

Two millennia-length juniper ring width chronologies, processed to preserve multi-centennial growth trends, are presented for the Alai Range of the western Tien Shan in Kirghizia. The chronologies average the information from seven near-timberline sampling sites, and likely reflect summer temperature variation. For comparison, chronologies are also built using standard dendrochronological techniques. We briefly discuss some qualities of these "inter-decadal” records, and show the low frequency components removed by the standardization process include a long-term negative trend in the first half of the last millennium and a long-term positive trend since about AD 1800. The multi-centennial scale Alai Range chronologies, where these trends are retained, are both systematically biased (but in an opposite sense) in their low frequency domains. Nevertheless, they represent the best constraints and estimates of long-term summer temperature variation, and reflect the Medieval Warm Period, the Little Ice Age, and a period of warming since about the middle of the nineteenth centur

Dealing with a traumatic past: the victim hearings of the South African truth and reconciliation commission and their reconciliation discourse

In the final years of the twentieth and the beginning of the twenty-first century, there has been a worldwide tendency to approach conflict resolution from a restorative rather than from a retributive perspective. The South African Truth and Reconciliation Commission (TRC), with its principle of 'amnesty for truth' was a turning point. Based on my discursive research of the TRC victim hearings, I would argue that it was on a discursive level in particular that the Truth Commission has exerted/is still exerting a long-lasting impact on South African society. In this article, three of these features will be highlighted and illustrated: firstly, the TRC provided a discursive forum for thousands of ordinary citizens. Secondly, by means of testimonies from apartheid victims and perpetrators, the TRC composed an officially recognised archive of the apartheid past. Thirdly, the reconciliation discourse created at the TRC victim hearings formed a template for talking about a traumatic past, and it opened up the debate on reconciliation. By discussing these three features and their social impact, it will become clear that the way in which the apartheid past was remembered at the victim hearings seemed to have been determined, not so much by political concerns, but mainly by social needs

Generalized estimating equations to estimate the ordered stereotype logit model for panel data

By modeling the effects of predictor variables as a multiplicative function of regression parameters being invariant over categories, and category-specific scalar effects, the ordered stereotype logit model is a flexible regression model for ordinal response variables. In this article, we propose a generalized estimating equations (GEE) approach to estimate the ordered stereotype logit model for panel data based on working covariance matrices, which are not required to be correctly specified. A simulation study compares the performance of GEE estimators based on various working correlation matrices and working covariance matrices using local odds ratios. Estimation of the model is illustrated using a real-world dataset. The results from the simulation study suggest that GEE estimation of this model is feasible in medium-sized and large samples and that estimators based on local odds ratios as realized in this study tend to be less efficient compared with estimators based on a working correlation matrix. For low true correlations, the efficiency gains seem to be rather small and if the working covariance structure is too flexible, the corresponding estimator may even be less efficient compared with the GEE estimator assuming independence. Like for GEE estimators more generally, if the true correlations over time are high, then a working covariance structure which is close to the true structure can lead to considerable efficiency gains compared with assuming independence.Peer ReviewedPostprint (published version

Vertical Artifacts in High-Resolution WorldView-2 and Worldview-3 Satellite Imagery of Aquatic Systems

Satellite image artefacts are features that appear in an image but not in the original imaged object and can negatively impact the interpretation of satellite data. Vertical artefacts are linear features oriented in the along-track direction of an image system and can present as either banding or striping; banding are features with a consistent width, and striping are features with inconsistent widths. This study used high-resolution data from DigitalGlobeʻs (now Maxar) WorldView-3 satellite collected at Lake Okeechobee, Florida (FL), on 30 August 2017. This study investigated the impact of vertical artefacts on both at-sensor radiance and a spectral index for an aquatic target as WorldView-3 was primarily designed as a land sensor. At-sensor radiance measured by six of WorldView-3ʻs eight spectral bands exhibited banding, more specifically referred to as non-uniformity, at a width corresponding to the multispectral detector sub-arrays that comprise the WorldView-3 focal plane. At-sensor radiance measured by the remaining two spectral bands, red and near-infrared (NIR) #1, exhibited striping. Striping in these spectral bands can be attributed to their time delay integration (TDI) settings at the time of image acquisition, which were optimized for land. The impact of vertical striping on a spectral index leveraging the red, red edge, and NIR spectral bands—referred to here as the NIR maximum chlorophyll index (MCINIR)—was investigated. Temporally similar imagery from the European Space Agencyʻs Sentinel-3 and Sentinel-2 satellites were used as baseline references of expected chlorophyll values across Lake Okeechobee as neither Sentinel-3 nor Sentinel-2 imagery showed striping. Striping was highly prominent in the MCINIR product generated using WorldView-3 imagery, as noise in the at-sensor radiance exceeded any signal of chlorophyll in the image. Adjusting the image acquisition parameters for future tasking of WorldView-3 or the functionally similar WorldView-2 satellite may alleviate these artefacts. To test this, an additional WorldView-3 image was acquired at Lake Okeechobee, FL, on 26 May 2021 in which the TDI settings and scan line rate were adjusted to improve the signal-to-noise ratio. While some evidence of non-uniformity remained, striping was no longer noticeable in the MCINIR product. Future image tasking over aquatic targets should employ these updated image acquisition parameters. Since the red and NIR #1 spectral bands are critical for inland and coastal water applications, archived images not collected using these updated settings may be limited in their potential for analysis of aquatic variables that require these two spectral bands to derive

Diabetes by Air, Land, and Sea: Effect of Deployments on HbA1c and BMI

INTRODUCTION: Service members (SMs) in the United States (U.S.) Armed Forces have diabetes mellitus at a rate of 2-3%. Despite having a chronic medical condition, they have deployed to environments with limited medical support. Given the scarcity of data describing how they fare in these settings, we conducted a retrospective study analyzing the changes in glycated hemoglobin (HbA1c) and body mass index (BMI) before and after deployment. MATERIALS AND METHODS: SMs from the U.S. Army, Air Force, Navy, and Marine Corps with diabetes who deployed overseas were identified through the Military Health System (MHS) Management Analysis and Reporting Tool and the Defense Manpower Data Center. Laboratory and pharmaceutical data were obtained from the MHS Composite Health Care System and the Pharmacy Data Transaction Service, respectively. Paired t-tests were conducted to calculate changes in HbA1c and BMI before and after deployment. RESULTS: SMs with diabetes completed 11,325 deployments of greater than 90 days from 2005 to 2017. Of these, 474 (4.2%) SMs had both HbA1c and BMI measurements within 90 days prior to departure and within 90 days of return. Most (84.2%) required diabetes medications: metformin in 67.3%, sulfonylureas in 19.0%, dipeptidyl peptidase-4 inhibitors in 13.9%, and insulin in 5.5%. Most SMs deployed with an HbA1c \u3c 7.0% (67.1%), with a mean predeployment HbA1c of 6.8%. Twenty percent deployed with an HbA1c between 7.0 and 7.9%, 7.2% deployed with an HbA1c between 8.0 and 8.9%, and 5.7% deployed with an HbA1c of 9.0% or higher. In the overall population and within each military service, there was no significant change in HbA1c before and after deployment. However, those with predeployment HbA1c \u3c 7.0% experienced a rise in HbA1c from 6.2 to 6.5% (P \u3c 0.001), whereas those with predeployment HbA1c values ≥7.0% experienced a decline from 8.0 to 7.5% (P \u3c 0.001). Those who deployed between 91 and 135 days had a decline in HbA1c from 7.1 to 6.7% (P = 0.010), but no significant changes were demonstrated in those with longer deployment durations. BMI declined from 29.6 to 29.3 kg/m2 (P \u3c 0.001), with other significant changes seen among those in the Army, Navy, and deployment durations up to 315 days. CONCLUSIONS: Most SMs had an HbA1c \u3c 7.0%, suggesting that military providers appropriately selected well-managed SMs for deployment. HbA1c did not seem to deteriorate during deployment, but they also did not improve despite a reduction in BMI. Concerning trends included the deployment of some SMs with much higher HbA1c, utilization of medications with adverse safety profiles, and the lack of HbA1c and BMI evaluation proximal to deployment departures and returns. However, for SMs meeting adequate glycemic targets, we demonstrated that HbA1c remained stable, supporting the notion that some SMs may safely deploy with diabetes. Improvement in BMI may compensate for factors promoting hyperglycemia in a deployed setting, such as changes in diet and medication availability. Future research should analyze in a prospective fashion, where a more complete array of diabetes and readiness-related measures to comprehensively evaluate the safety of deploying SMs with diabetes

Glycemic Benefits with Adherence to testosterone therapy in men with hypogonadism and type 2 diabetes mellitus.

BACKGROUND: While previous studies have demonstrated testosterone\u27s beneficial effects on glycemic control in men with hypogonadism and Type 2 Diabetes, the extent to which these improvements are observed based on the degree of treatment adherence has been unclear. OBJECTIVES: To evaluate the effects of long-term testosterone therapy in A1C levels in men with Type 2 Diabetes Mellitus and hypogonadism, controlling for BMI, pre-treatment A1C, and age among different testosterone therapy adherence groups. MATERIALS AND METHODS: We performed a retrospective analysis of 1737 men with diabetes and hypogonadism on testosterone therapy for 5 years of data from 2008-2018, isolating A1C, lipid panels, and BMI results for analysis. Subjects were categorized into adherence groups based on quartiles of the proportion of days covered (\u3e 75% of days, 51-75% of days, 26-50% of days and 0-25% of days), with \u3e75% of days covered considered adherent to therapy. RESULTS: Pre-treatment median A1C was 6.8%. Post-treatment median A1C was 7.1%. The adherent group, \u3e75%, was the only group notable for a decrease in A1C, with a median decrease of -0.2 (p = 0.0022). BMI improvement was associated with improved post-treatment A1C (p = 0.007). When controlling for BMI, age, and pre-treatment A1C, the \u3e75% adherence group was associated with improved post-treatment A1C (p \u3c 0.001). DISCUSSION: When controlling for all studied variables, testosterone adherence was associated with improved post-treatment A1C. The higher the initial A1C at the initiation of therapy, the higher the potential for lowering the patient\u27s A1C with \u3e75% adherence. Further, all groups showed some reduction in BMI, which may indicate that testosterone therapy may affect A1C independent of weight loss. CONCLUSION: Even when controlling for improved BMI, pre-treatment A1C, and age, testosterone positively impacted glycemic control in diabetes patients with hypogonadism, with the most benefit noted in those most adherent to therapy (\u3e75%)

Effect of Military Deployment on Diabetes Mellitus in Air Force Personnel

Introduction: Military deployments relocate service members to austere locations with limited medical capabilities, raising uncertainties whether members with diabetes can participate safely. Military regulations require a medical clearance for service members with diabetes prior to deployment, but there is a dearth of data that can guide the provider in this decision. To alleviate the lack of evidence in this area, we analyzed the change in glycated hemoglobin (HbA1c) and body mass index (BMI) before and after a deployment among active duty U.S. Air Force personnel who deployed with diabetes. Materials and Methods: A retrospective analysis was conducted using HbA1c and BMI values obtained within 3 mo before and within 3 mo after repatriation from a deployment of at least 90 d between January 1, 2004 through December 31, 2014. The study population consisted of 103 and 195 subjects who had an available pre- and post-deployment HbA1c and BMI values, respectively. Paired t-tests were conducted to determine significant differences in HbA1C and BMI values. Results: The majority (73.8%) of members had a HbA1c7%. BMI declined for the overall population (28.3 kg/m2 vs. 27.7 kg/m2, p \u3c 0.0001) and for most of the subgroups. Conclusion: Air Force service members who deployed with diabetes, including those with a HbA1c \u3e 7%, experienced a statistically significant improvement in HbA1c and BMI upon repatriation. A prospective study design in the future can better reconcile the effect of a military deployment on a more comprehensive array of diabetes parameters

Evaluation of Total Daily Dose and Glycemic Control for Patients Taking U-500 Regular Insulin Admitted to the Hospital

OBJECTIVE: Patients using U-500 regular insulin are severely insulin resistant, requiring high doses of insulin. It has been observed that a patient\u27s insulin requirements may dramatically decrease during hospitalization. This study sought to systematically investigate this phenomenon. METHODS: We performed a retrospective chart review of patients with U-500 insulin outpatient regimens who were admitted to the San Antonio Military Medical Center over a 5-year period. Each patient\u27s outpatient total daily dose (TDD) of insulin was compared to the average inpatient TDD. The outpatient estimated average glucose (eAG) was calculated from the glycated hemoglobin (HbA1c) and compared to the average inpatient glucose. RESULTS: There were 27 patients with a total of 62 separate admissions. The average age was 64.4 years, with a mean body mass index of 38.9 kg/m CONCLUSION: U-500 insulin is prone to errors in the hospital setting, so conversion to U-100 insulin is a preferred option. Despite a significant reduction in insulin TDD, these patients had clinically similar glucose levels. Therefore, patients taking U-500 insulin as an outpatient can be converted to a U-100 basal-bolus regimen with at least a 50% reduction of their outpatient TDD. ABBREVIATIONS: BG = blood glucose eAG = estimated average glucose HbA1c = glycated hemoglobin NPO = nil per os SPSS = Statistical Package for the Social Sciences TDD = total daily dose

Linear Estimation of Location and Scale Parameters Using Partial Maxima

Consider an i.i.d. sample X^*_1,X^*_2,...,X^*_n from a location-scale family, and assume that the only available observations consist of the partial maxima (or minima)sequence, X^*_{1:1},X^*_{2:2},...,X^*_{n:n}, where X^*_{j:j}=max{X^*_1,...,X^*_j}. This kind of truncation appears in several circumstances, including best performances in athletics events. In the case of partial maxima, the form of the BLUEs (best linear unbiased estimators) is quite similar to the form of the well-known Lloyd's (1952, Least-squares estimation of location and scale parameters using order statistics, Biometrika, vol. 39, pp. 88-95) BLUEs, based on (the sufficient sample of) order statistics, but, in contrast to the classical case, their consistency is no longer obvious. The present paper is mainly concerned with the scale parameter, showing that the variance of the partial maxima BLUE is at most of order O(1/log n), for a wide class of distributions.Comment: This article is devoted to the memory of my six-years-old, little daughter, Dionyssia, who leaved us on August 25, 2010, at Cephalonia isl. (26 pages, to appear in Metrika