High-throughput optical thickness and size characterization of 2D materials.

We describe a method using simple optical microscopy and image processing that simultaneously characterizes thousands of nanosheets in a sample area on the order of 1 mm2. Including data acquisition and processing, both the number of atomic layers and the lateral sizes of all sheets can be obtained within a few hours-approximately 100 times faster than with previous methods, such as atomic force microscopy. This is achieved by normalizing the optical image based on substrate brightness, which eliminates inhomogeneities usually limiting optical techniques. Ultimately, the method enables robust statistical analysis of populations of nanosheet materials. We demonstrate the utility of this method by examining fractions made from a sample of graphene oxide (GO) made using an emulsion-based method. Beyond providing the morphological composition of the samples, the reported method is sensitive enough to provide information about the oxidation level of a population of GO sheets and, correspondingly, optical constants of the material.

Late Pleistocene fishes of the Tennessee River Basin: an analysis of a late Pleistocene freshwater fish fauna from Bell Cave (site ACb-2) in Colbert County, Alabama, USA.

The Tennessee River Basin is considered one of the most important regions for freshwater biodiversity anywhere on the globe. The Tennessee River Basin currently includes populations of at least half of the described contemporary diversity of extant North American freshwater fishes, crayfish, mussel, and gastropod species. However, comparatively little is known about the biodiversity of this basin from the Pleistocene Epoch, particularly the late Pleistocene (∼10,000 to 30,000 years B.P.) leading to modern Holocene fish diversity patterns. The objective of this study was to describe the fish assemblages of the Tennessee River Basin from the late Pleistocene using a series of faunas from locales throughout the basin documented from published literature, unpublished reports, and an undocumented fauna from Bell Cave (site ACb-2, Colbert County, AL). Herein we discuss 41 unequivocal taxa from 10 late Pleistocene localities within the basin and include a systematic discussion of 11 families, 19 genera, and 24 identifiable species (28 unequivocal taxa) specific to the Bell Cave locality. Among the described fauna are several extirpated (e.g., Northern Pike Esox lucius, Northern Madtom Noturus stigmosus) and a single extinct (Harelip Sucker Moxostoma lacerum) taxa that suggest a combination of late Pleistocene displacement events coupled with more recent changes in habitat that have resulted in modern basin diversity patterns. The Bell Cave locality represents one of the most intact Pleistocene freshwater fish deposits anywhere in North America. Significant preservational, taphonomic, sampling, and identification biases preclude the identification of additional taxa. Overall, this study provides a detailed look into paleo-river ecology, as well as freshwater fish diversity and distribution leading up to the contemporary biodiversity patterns of the Tennessee River Basin and Mississippi River Basin as a whole.

Earliest Pottery on New Guinea Mainland Reveals Austronesian Influences in Highland Environments 3000 Years Ago.

Austronesian speaking peoples left Southeast Asia and entered the Western Pacific c.4000-3000 years ago, continuing on to colonise Remote Oceania for the first time, where they became the ancestral populations of Polynesians. Understanding the impact of these peoples on the mainland of New Guinea before they entered Remote Oceania has eluded archaeologists. New research from the archaeological site of Wañelek in the New Guinea Highlands has broken this silence. Petrographic and geochemical data from pottery and new radiocarbon dating demonstrates that Austronesian influences penetrated into the highland interior by 3000 years ago. One potsherd was manufactured along the northeast coast of New Guinea, whereas others were manufactured from inland materials. These findings represent the oldest securely dated pottery from an archaeological context on the island of New Guinea. Additionally, the pottery comes from the interior, suggesting the movements of people and technological practices, as well as objects at this time. The antiquity of the Wañelek pottery is coincident with the expansion of Lapita pottery in the Western Pacific. Such occupation also occurs at the same time that changes have been identified in subsistence strategies in the archaeological record at Kuk Swamp suggesting a possible link between the two.

Stone tools from the ancient Tongan state reveal prehistoric interaction centers in the Central Pacific.

Tonga was unique in the prehistoric Pacific for developing a maritime state that integrated the archipelago under a centralized authority and for undertaking long-distance economic and political exchanges in the second millennium A.D. To establish the extent of Tonga's maritime polity, we geochemically analyzed stone tools excavated from the central places of the ruling paramounts, particularly lithic artifacts associated with stone-faced chiefly tombs. The lithic networks of the Tongan state focused on Samoa and Fiji, with one adze sourced to the Society Islands 2,500 km from Tongatapu. To test the hypothesis that nonlocal lithics were especially valued by Tongan elites and were an important source of political capital, we analyzed prestate lithics from Tongatapu and stone artifacts from Samoa. In the Tongan state, 66% of worked stone tools were long-distance imports, indicating that interarchipelago connections intensified with the development of the Tongan polity after A.D. 1200. In contrast, stone tools found in Samoa were from local sources, including tools associated with a monumental structure contemporary with the Tongan state. Network analysis of lithics entering the Tongan state and of the distribution of Samoan adzes in the Pacific identified a centralized polity and the products of specialized lithic workshops, respectively. These results indicate that a significant consequence of social complexity was the establishment of new types of specialized sites in distant geographic areas. Specialized sites were loci of long-distance interaction and formed important centers for the transmission of information, people, and materials in prehistoric Oceania.

Periodic planar disc packings.

Several conditions are given when a packing of equal discs in a torus is locally maximally dense, where the torus is defined as the quotient of the plane by a two-dimensional lattice. Conjectures are presented that claim that the density of any collectively jammed packing, whose graph does not consist of all triangles, and the torus lattice is the standard triangular lattice, is at most (n/(n + 1))π√12, where n is the number of packing discs in the torus. Several classes of collectively jammed packings are presented where the conjecture holds.

Baseline characteristics and treatment outcomes in prescription opioid dependent patients with and without co-occurring psychiatric disorder.

BACKGROUND: Given the growing prevalence of prescription opioid dependence and the considerable rates of additional psychopathology in drug dependence, we examined the association between the presence of a co-occurring Axis I psychiatric disorder and sociodemographic and clinical characteristics in this secondary analysis of patients entering a treatment study for dependence on prescription opioids. Treatment outcomes were also compared. METHODS: Patients dependent on prescription opioids participated in a multi-site, two-phase, randomized, controlled trial to assess different lengths of buprenorphine-naloxone pharmacotherapy and different intensities of counseling (Clinicaltrials.gov identifier: NCT00316277). Among the 653 participants entering the first phase of the trial, 360 entered the second phase, receiving 12 weeks of buprenorphine-naloxone treatment; they are reported here. Half of those participants (180/360) had a current co-occurring psychiatric disorder in addition to substance dependence. RESULTS: Sociodemographic characteristics were similar overall between those with and without a co-occurring psychiatric disorder, but women were 1.6 times more likely than men to have a co-occurring disorder. On several clinical indicators at baseline, participants with a co-occurring disorder had greater impairment. However, they had better opioid use outcomes at the conclusion of 12 weeks of buprenorphine-naloxone stabilization than did participants without a co-occurring disorder. CONCLUSIONS: Prescription opioid-dependent patients with a co-occurring psychiatric disorder had a better response to buprenorphine-naloxone treatment despite demonstrating greater impairment at baseline. Additional research is needed to determine the mechanism of this finding and to adapt treatments to address this population.

Comment on "Apatite 4He/3He and (U-Th)/He evidence for an ancient Grand Canyon".

Flowers and Farley (Reports, 21 December 2012, p. 1616; published online 29 November 2012) propose that the Grand Canyon is 70 million years old. Starkly contrasting models for the age of the Grand Canyon-70 versus 6 million years-can be reconciled by a shallow paleocanyon that was carved in the eastern Grand Canyon 25 to 15 million years ago (Ma), negating the proposed 70 Ma and 55 Ma paleocanyons. Cooling models and geologic data are most consistent with a 5 to 6 Ma age for western Grand Canyon and Marble Canyon.

Adjunctive counseling during brief and extended buprenorphine-naloxone treatment for prescription opioid dependence: a 2-phase randomized controlled trial.

CONTEXT: No randomized trials have examined treatments for prescription opioid dependence, despite its increasing prevalence. OBJECTIVE: To evaluate the efficacy of brief and extended buprenorphine hydrochloride-naloxone hydrochloride treatment, with different counseling intensities, for patients dependent on prescription opioids. DESIGN: Multisite, randomized clinical trial using a 2-phase adaptive treatment research design. Brief treatment (phase 1) included 2-week buprenorphine-naloxone stabilization, 2-week taper, and 8-week postmedication follow-up. Patients with successful opioid use outcomes exited the study; unsuccessful patients entered phase 2: extended (12-week) buprenorphine-naloxone treatment, 4-week taper, and 8-week postmedication follow-up. SETTING: Ten US sites. Patients A total of 653 treatment-seeking outpatients dependent on prescription opioids. INTERVENTIONS: In both phases, patients were randomized to standard medical management (SMM) or SMM plus opioid dependence counseling; all received buprenorphine-naloxone. MAIN OUTCOME MEASURES: Predefined "successful outcome" in each phase: composite measures indicating minimal or no opioid use based on urine test-confirmed self-reports. RESULTS: During phase 1, only 6.6% (43 of 653) of patients had successful outcomes, with no difference between SMM and SMM plus opioid dependence counseling. In contrast, 49.2% (177 of 360) attained successful outcomes in phase 2 during extended buprenorphine-naloxone treatment (week 12), with no difference between counseling conditions. Success rates 8 weeks after completing the buprenorphine-naloxone taper (phase 2, week 24) dropped to 8.6% (31 of 360), again with no counseling difference. In secondary analyses, successful phase 2 outcomes were more common while taking buprenorphine-naloxone than 8 weeks after taper (49.2% [177 of 360] vs 8.6% [31 of 360], P < .001). Chronic pain did not affect opioid use outcomes; a history of ever using heroin was associated with lower phase 2 success rates while taking buprenorphine-naloxone. CONCLUSIONS: Prescription opioid-dependent patients are most likely to reduce opioid use during buprenorphine-naloxone treatment; if tapered off buprenorphine-naloxone, even after 12 weeks of treatment, the likelihood of an unsuccessful outcome is high, even in patients receiving counseling in addition to SMM.

Neural response telemetry results with the nucleus 24 contour in a perimodiolar position.

OBJECTIVE: The purpose of the study was to analyze changes in neural response telemetry using the Cochlear Nucleus 24 Contour before and after stylet removal in a human model. STUDY DESIGN: Prospective study. SETTING: Tertiary referral center. PATIENTS: Twelve patients (23-72 years old) undergoing cochlear implantation, using the Nucleus 24 Contour implant, secondary to congenital and age-related hearing loss. INTERVENTION: Cochlear implantation with Cochlear Nucleus 24 Contour implant. MAIN OUTCOME MEASURE: Neural response telemetry thresholds were recorded initially with the stylet in and then with the stylet out during the implant procedure. RESULTS: Stimulus levels to obtain neural response telemetry threshold after stylet removal were statistically lower after the stylet was removed. CONCLUSION: The Nucleus 24 Contour achieves a perimodiolar position once the stylet is removed, and this leads to reduction in the current required to elicit a threshold neural response telemetry response.