Searching for Gravitational Waves from Cosmological Phase Transitions with the NANOGrav 12.5-Year Dataset.

We search for a first-order phase transition gravitational wave signal in 45 pulsars from the NANOGrav 12.5-year dataset. We find that the data can be modeled in terms of a strong first order phase transition taking place at temperatures below the electroweak scale. However, we do not observe any strong preference for a phase-transition interpretation of the signal over the standard astrophysical interpretation in terms of supermassive black hole mergers; but we expect to gain additional discriminating power with future datasets, improving the signal to noise ratio and extending the sensitivity window to lower frequencies. An interesting open question is how well gravitational wave observatories could separate such signals.

Should prenatal hydronephrosis that resolves before birth be followed postnatally? Analysis and comparison to persistent prenatal hydronephrosis.

BACKGROUND: Prenatal ultrasonography has greatly enhanced detection of congenital genitourinary abnormalities. However, although persistent prenatal hydronephrosis (PPH) is typically imaged and followed postnatally, it remains unclear if prenatal hydronephrosis that resolves in utero (RPH) should be similarly managed. We determined postnatal abnormalities associated with RPH and compared these to those associated with PPH. METHODS: We performed a retrospective review of all consecutive patients evaluated for prenatal hydronephrosis over 24 months. Patients were followed prenatally with serial ultrasounds and postnatally with ultrasonography and a voiding cystourethrogram. RESULTS: Of the consecutive 165 patients enrolled in the study, 72 had RPH. The average prenatal anterior-posterior renal pelvis length was significantly longer in patients with PPH (5.5 mm) than in those with RPH (4.9 mm) (p = 0.01). Recurrent postnatal hydronephrosis occurred in 44% of patients with RPH, with eventual resolution in 34% of those affected. In comparison, 29% of PPH cases resolved postnatally. Mean time to resolution was statistically shorter for PPH (116 days) than for RPH (175 days) (p = 0.01). Seven PPH patients required surgery, while no RPH patients needed intervention (difference was statistically significant). CONCLUSIONS: A significant number of RPH children had postnatal hydronephrosis. Despite a slower resolution time, no children with RPH required intervention. Although RPH may recur postnatally, the significantly lower chance of intervention being required suggests that these children may not require postnatal imaging.

Disparities Made Invisible: Gaps in COVID-19 Data for American Indian and Alaska Native Populations.

Introduction: Complete COVID-19 data for American Indian/Alaska Native (AI/AN) populations are critical to equitable pandemic response. Methods: We used the COVID-19 U.S. State Policy database to document gaps in COVID-19 data reporting for AI/AN people. Results: Sixty-four percent of states do not report AI/AN data for at least one COVID-19 health metric: cases, hospitalizations, deaths, or vaccinations. Discussion: The lack of AI/AN-specific data masks the disproportionate burden of COVID-19 and presents challenges to COVID-19 prevention, policy implementation, and health equity. Conclusions: Public-facing data disaggregated by race may facilitate rapid response COVID-19 research and policymaking to support AI/AN communities.

Operation Aftershock: the U.S. military disaster response to the Yogyakarta earthquake May through June 2006.

The U.S. military has recently been involved in many humanitarian assistance and disaster response missions around the world. This newfound role is in response to the U.S. government's desire to use "medical diplomacy" rather than "military might" to shape its relationship with foreign governments. With each of these humanitarian assistance and disaster response missions, the U.S. military has learned how to more rapidly insert desperately needed services and skill sets into disaster-struck communities, how to arrange for in-country services (translation services, transportation, etc.) that cannot be readily brought in, and how to work closely with foreign governments and nongovernmental organizations to determine their needs and expectations without the U.S. military appearing as if it were trying to establish a permanent presence.

Dietary phosphorus reduction by pretreatment of human breast milk with sevelamer.

Hyperphosphatemia leading to hyperparathyroidism and ultimately renal osteodystrophy is a well-known complication of chronic renal failure. A new hydrogel binder, sevelamer, has recently become available for use in hyperphosphatemic patients with renal failure. We had previously mixed the capsule with pumped breast milk and formula, but discovered that the hydrogel formed a viscous solution that infants were unable or unwilling to swallow. We therefore evaluated the phosphorus content of fresh and frozen breast milk before and after treating with different doses of sevelamer at different temperatures and for varying lengths of time. The hydrogel bound promptly to phosphorus, reducing the phosphorus content 78% within 5 min. The viscous hydrogel settled to the bottom of the container within 10 min allowing the supernatant to be easily decanted. We also evaluated the breast milk for changes in other electrolytes, osmolality, pH, and macronutrient content. These results show that fresh or frozen breast milk can be safely pretreated with sevelamer without significantly changing its macronutrient or ionic content, with the exception of calcium and protein. The supernatant can be fed to infants or instilled through a gastrostomy tube without difficulty since the viscous hydrogel settles rapidly to the bottom of the container.

Presentation of idiopathic retroperitoneal fibrosis in the pediatric population.

Idiopathic fibrosis of the retroperitoneum is rare in childhood. The authors describe an 11-year-old boy who presented with progressive renal failure, bilateral hydronephrosis, hypertension, and elevated erythrocyte sedimentation rate (ESR) owing to retroperitoneal fibrosis. Ureterolysis was performed with improvement in his creatinine level and blood pressure. The soft tissue mass consisted of dense collagenous fibers consistent with retroperitoneal fibrosis. Postoperatively, he received steroids and azathioprine. Retroperitoneal fibrosis in the pediatric population is rare with only 23 cases reported in the English-language literature. Treatment includes pulsed steroid regimens, ureteral catheterization, and retroperitoneal exploration with ureterolysis. If allowed to progress, renal failure can result and lead to death. The etiology of retroperitoneal fibrosis in the pediatric patient may include autoimmune diseases, infection, and neoplasm, but most cases are idiopathic. Retroperitoneal fibrosis should be considered in patients with an elevated ESR, hypertension, renal failure, and hydronephrosis. Evaluation also should include a search for autoimmune diseases and malignancy.

Mycobacterial peritonitis in pediatric peritoneal dialysis patients.

Peritonitis is the most common complication and the leading cause of death in pediatric peritoneal dialysis (PD) patients. According to the most recent data available from the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS), approximately 25% of pediatric PD patients who die succumb to infection. There are no reported cases of Mycobacterium tuberculosis (MTB) or Mycobacterium avium-intracellulare peritonitis in the NAPRTCS registry. With an increasing incidence of MTB worldwide and the impairment of cellular immunity in chronic renal failure patients, it is not surprising that mycobacterium peritonitis can occur in PD patients. We report two pediatric PD patients with mycobacterial peritoneal infection diagnosed over an 11-year period at our institution. One patient presented with a malfunctioning Tenckhoff catheter and again 3 years later with hyponatremia and ascites. The other presented with recurrent culture-negative peritonitis. These cases illustrate the importance of more extensive evaluation of PD complications, to include evaluation for mycobacterium with special media or peritoneal biopsy, in the above clinical settings if the routine work-up is unrevealing.