A general theory of minimum aberration and its applications

Minimum aberration is an increasingly popular criterion for comparing and assessing fractional factorial designs, and few would question its importance and usefulness nowadays. In the past decade or so, a great deal of work has been done on minimum aberration and its various extensions. This paper develops a general theory of minimum aberration based on a sound statistical principle. Our theory provides a unified framework for minimum aberration and further extends the existing work in the area. More importantly, the theory offers a systematic method that enables experimenters to derive their own aberration criteria. Our general theory also brings together two seemingly separate research areas: one on minimum aberration designs and the other on designs with requirement sets. To facilitate the design construction, we develop a complementary design theory for quite a general class of aberration criteria. As an immediate application, we present some construction results on a weak version of this class of criteria.Comment: Published at http://dx.doi.org/10.1214/009053604000001228 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Some results on 2n−m2^{n-m} designs of resolution IV with (weak) minimum aberration

It is known that all resolution IV regular $2^{n-m}$ designs of run size $N=2^{n-m}$ where $5N/16<n<N/2$ must be projections of the maximal even design with $N/2$ factors and, therefore, are even designs. This paper derives a general and explicit relationship between the wordlength pattern of any even $2^{n-m}$ design and that of its complement in the maximal even design. Using these identities, we identify some (weak) minimum aberration $2^{n-m}$ designs of resolution IV and the structures of their complementary designs. Based on these results, several families of minimum aberration $2^{n-m}$ designs of resolution IV are constructed.Comment: Published in at http://dx.doi.org/10.1214/08-AOS670 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

A complementary design theory for doubling

Chen and Cheng [Ann. Statist. 34 (2006) 546--558] discussed the method of doubling for constructing two-level fractional factorial designs. They showed that for $9N/32\le n\le 5N/16$, all minimum aberration designs with $N$ runs and $n$ factors are projections of the maximal design with $5N/16$ factors which is constructed by repeatedly doubling the $2^{5-1}$ design defined by $I=ABCDE$. This paper develops a general complementary design theory for doubling. For any design obtained by repeated doubling, general identities are established to link the wordlength patterns of each pair of complementary projection designs. A rule is developed for choosing minimum aberration projection designs from the maximal design with $5N/16$ factors. It is further shown that for $17N/64\le n\le 5N/16$, all minimum aberration designs with $N$ runs and $n$ factors are projections of the maximal design with $N$ runs and $5N/16$ factors.Comment: Published in at http://dx.doi.org/10.1214/009005360700000712 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

A Panel Data Approach for Program Evaluation — Measuring the Benefits of Political and Economic Integration of Hong Kong with Mainland China

We propose a simple to implement panel data method to evaluate the impacts of social policy. The basic idea is to exploit the dependence among cross-sectional units to construct the counterfactuals. The cross-sectional correlations are attributed to the presence of some (unobserved) common factors. However, instead of trying to estimate the unobserved factors, we propose to use observed data. We use a panel of 24 countries to evaluate the impact of political and economic integration of Hong Kong (HK) with Mainland China. We find that the political integration hardly had any impact on the growth of the Hong Kong economy. However, the economic integration has raised HK’s annual real GDP by about 4%.

Etiology and Treatment of Childhood Peptic Ulcer Disease in Taiwan: A Single Center 9-Year Experience

Background/PurposePeptic ulcer disease (PUD) in children is relatively rare as compared with adults. This study aimed to assess the etiology, clinical and histological characteristics, and treatment of PUD in children.MethodsAll children aged < 18 years with an endoscopic diagnosis of PUD were enrolled in a tertiary referral center. The demographic data, clinical, endoscopic, and histological findings were compared between patients with different causes of PUD.ResultsFrom 1234 endoscopic examinations, 67 (5.4%) children (median age, 11.4 years) with gastric ulcer (GU; n = 27) or duodenal ulcer (DU; n = 40) were included. Thirty-two (47.7%) of them had Helicobacter pylori infection and 11 (16.5%) had previous use of non-steroidal anti-inflammatory drugs (NSAIDs). Non-H. pylori, non-NSAID PUD was found in 24 (35.8%) patients. Children with H. pylori-related PUD had a significantly higher mean age, antral chronic inflammatory score, rate of familial PUD, and presence of DU and nodular gastritis than those with NSAID-related and non-H. pylori, non-NSAID PUD (p < 0.01). In contrast, children with NSAID-related PUD had a higher rate of upper gastrointestinal bleeding, associated with acute febrile disease, than those with H. pylori-related and non-H. pylori, non-NSAID PUD (p < 0.05). All but two patients with non-H. pylori, non-NSAID PUD were disease free after H. pylori eradication and proton pump inhibitor treatment for 1–2 months.ConclusionIn children, H. pylori-related PUD is associated with familial peptic ulcer and the presence of DU. However, short-term NSAID use is correlated highly with GU. The outcome of childhood PUD is good

Distribution and associated factors of optic disc diameter and cup-to-disc ratio in an elderly Chinese population

AbstractBackgroundGlaucoma is the second leading cause of blindness worldwide and East Asian people account for almost half of those affected. Vertical elongation of the optic cup is a characteristic feature of glaucoma. However, there is a significant overlap in the vertical cup-to-disc ratio (VCDR) between normal eyes and eyes affected by glaucoma. The purpose of this study was to determine the distribution of VCDR and vertical disc diameter (VDD) and their predictive factors in a population of elderly Chinese residents in Taiwan.MethodsFour hundred and sixty elderly Chinese residents aged 72 years and older in the Shihpai district, Taipei, Taiwan participated in this study. Slit lamp biomicroscopic measurement of the VCDR and VDD after pupil dilation with a 78 diopter lens was performed by one glaucoma specialist. Multiple linear regression analyses were used to fit the best model for independent variables.ResultsThe VCDR was recorded for 438 right eyes and 430 left eyes. After excluding participants with glaucoma, the mean ± SD VCDR was 0.44 ± 0.17 for both eyes, and the 97.5th percentile was 0.8. A greater VCDR was associated with a longer axial length [VCDR = −0.47 + 0.04(axial length)] under multiple regression analysis. The VDD was obtained for 420 right eyes and 406 left eyes. The mean ± SD VDD for all participants was 1.77 ± 0.22 mm for the right eye and 1.79 ± 0.22 mm for the left eye. A higher body mass index (BMI) and a longer axial length were significantly associated with a larger VDD under multiple regression analysis. [VDD = −0.05 + 0.07 (axial length) + 0.06 (obesity); if BMI <24, then obesity = 0; if BMI ≥24, then obesity = 1]. A larger VDD was associated with a larger VCDR (p < 0.001) and the VCDR could be predicted by the equation VCDR = −0.07 + 0.3VDD.ConclusionA greater VCDR was related to a longer axial length. A greater VDD was related to a higher BMI and a longer axial length

Increased Risk for Entamoeba histolytica Infection and Invasive Amebiasis in HIV Seropositive Men Who Have Sex with Men in Taiwan

Entamoeba histolytica, morphologically identical to but genetically different from E. dispar and E. moshkovskii, is the causative agent of amebiasis. Recently there have been reports of increased risk for amebiasis among men who have sex with men (MSM) due to oral-anal sexual contact in several developed countries. In this longitudinal follow-up study, the incidence of amebiasis was determined among HIV-infected patients using serological and specific amebic antigen assays. DNA extracted from stool samples containing E. histolytica were analyzed by PCR, sequenced, and compared. Clinical manifestations and treatment response of invasive amebiasis in HIV-infected patients were reviewed. The results demonstrated that HIV-infected MSM were at significantly higher risk of amebiasis than patients from other risk groups. Clustering of E. histolytica isolates by sequencing analyses from geographically unrelated patients suggested person-to-person transmission. Despite immunosuppression, amebic liver abscesses and colitis responded favorably to metronidazole therapy. It is important to investigate in areas of high incidence of both amebiasis and HIV (sub-Saharan Africa) how generalizable these findings are

ATF3 Sustains IL-22-Induced STAT3 Phosphorylation to Maintain Mucosal Immunity Through Inhibiting Phosphatases

In gut epithelium, IL-22 transmits signals through STAT3 phosphorylation (pSTAT3) which provides intestinal immunity. Many components in the IL-22-pSTAT3 pathway have been identified as risk factors for inflammatory bowel disease (IBD) and some of them are considered as promising therapeutic targets. However, new perspectives are still needed to understand IL-22-pSTAT3 signaling for effective clinical interventions in IBD patients. Here, we revealed activating transcription factor 3 (ATF3), recently identified to be upregulated in patients with active IBD, as a crucial player in the epithelial IL-22-pSTAT3 signaling cascade. We found ATF3 is central to intestinal homeostasis and provides protection during colitis. Loss of ATF3 led to decreased crypt numbers, more shortened colon length, impaired ileal fucosylation at the steady state, and lethal disease activity during DSS-induced colitis which can be effectively ameliorated by rectal transplantation of wild-type colonic organoids. Epithelial stem cells and Paneth cells form a niche to orchestrate epithelial regeneration and host-microbe interactions, and IL-22-pSTAT3 signaling is a key guardian for this niche. We found ATF3 is critical for niche maintenance as ATF3 deficiency caused compromised stem cell growth and regeneration, as well as Paneth cell degeneration and loss of anti-microbial peptide (AMP)-producing granules, indicative of malfunction of Paneth/stem cell network. Mechanistically, we found IL-22 upregulates ATF3, which is required to relay IL-22 signaling leading to STAT3 phosphorylation and subsequent AMP induction. Intriguingly, ATF3 itself does not act on STAT3 directly, instead ATF3 regulates pSTAT3 by negatively targeting protein tyrosine phosphatases (PTPs) including SHP2 and PTP-Meg2. Furthermore, we identified ATF3 is also involved in IL-6-mediated STAT3 activation in T cells and loss of ATF3 leads to reduced capacity of Th17 cells to produce their signature cytokine IL-22 and IL-17A. Collectively, our results suggest that via IL-22-pSTAT3 signaling in the epithelium and IL-6-pSTAT3 signaling in Th17 cells, ATF3 mediates a cross-regulation in the barrier to maintain mucosal homeostasis and immunity

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely