To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Alcohol, cannabis, and nicotine use are highly comorbid and alarmingly prevalent in young adults. The hippocampus may be particularly sensitive to substance exposure. This remains largely untested in humans and familial risk may confound exposure effects. We extend prior work on alcohol and hippocampal volume in women by testing common and unique substance use effects and the potential moderating role of sex on hippocampal volume during emerging adulthood. A quasi-experimental cotwin control (CTC) design was used to separate familial risk from exposure consequences.
In a population-based sample of 435 24-year-old same-sex twins (58% women), dimensional measures (e.g. frequency, amount) of alcohol, cannabis, and nicotine use across emerging adulthood were assessed. Hippocampal volume was assessed using MRI.
Greater substance use was significantly associated with lower hippocampal volume for women but not men. The same pattern was observed for alcohol, cannabis, and nicotine. CTC analyses provided evidence that hippocampal effects likely reflected familial risk and the consequence of substance use in general and alcohol and nicotine in particular; cannabis effects were in the expected direction but not significant. Within-pair mediation analyses suggested that the effect of alcohol use on the hippocampus may reflect, in part, comorbid nicotine use.
The observed hippocampal volume deviations in women likely reflected substance-related premorbid familial risk and the consequences of smoking and, to a lesser degree, drinking. Findings contribute to a growing body of work suggesting heightened risk among women toward experiencing deleterious effects of substance exposure on the still-developing young adult hippocampus.
To better characterize brain-based mechanisms of polygenic liability for psychopathology and psychological traits, we extended our previous report (Liu et al. Psychophysiological endophenotypes to characterize mechanisms of known schizophrenia genetic loci. Psychological Medicine, 2017), focused solely on schizophrenia, to test the association between multivariate psychophysiological candidate endophenotypes (including novel measures of θ/δ oscillatory activity) and a range of polygenic scores (PGSs), namely alcohol/cannabis/nicotine use, an updated schizophrenia PGS (containing 52 more genome-wide significant loci than the PGS used in our previous report) and educational attainment.
A large community-based twin/family sample (N = 4893) was genome-wide genotyped and imputed. PGSs were constructed for alcohol use, regular smoking initiation, lifetime cannabis use, schizophrenia, and educational attainment. Eleven endophenotypes were assessed: visual oddball task event-related electroencephalogram (EEG) measures (target-related parietal P3 amplitude, frontal θ, and parietal δ energy/inter-trial phase clustering), band-limited resting-state EEG power, antisaccade error rate. Principal component analysis exploited covariation among endophenotypes to extract a smaller number of meaningful dimensions/components for statistical analysis.
Endophenotypes were heritable. PGSs showed expected intercorrelations (e.g. schizophrenia PGS correlated positively with alcohol/nicotine/cannabis PGSs). Schizophrenia PGS was negatively associated with an event-related P3/δ component [β = −0.032, nonparametric bootstrap 95% confidence interval (CI) −0.059 to −0.003]. A prefrontal control component (event-related θ/antisaccade errors) was negatively associated with alcohol (β = −0.034, 95% CI −0.063 to −0.006) and regular smoking PGSs (β = −0.032, 95% CI −0.061 to −0.005) and positively associated with educational attainment PGS (β = 0.031, 95% CI 0.003–0.058).
Evidence suggests that multivariate endophenotypes of decision-making (P3/δ) and cognitive/attentional control (θ/antisaccade error) relate to alcohol/nicotine, schizophrenia, and educational attainment PGSs and represent promising targets for future research.
Subclinical adolescent alcohol use is highly prevalent and may have deleterious effects on important psychosocial and brain outcomes. Prior research has focused on identifying endophenotypes of pathological drinking, and the predictors of normative drinking remain understudied. This study investigated the incremental predictive value of two potential psychophysiological endophenotypes, P3 amplitude (an index of decision making) and midfrontal theta power (a correlate of attentional control), for prospectively predicting the expression and initiation of alcohol use emerging in adolescence.
A large (N = 594) epidemiological sample was prospectively assessed at ages 11/14/17. Alcohol/substance use was assessed at all ages via a computerized self-report inventory. EEG was recorded at age-14 during a visual oddball task to elicit P3 and theta.
Reduced target-related P3 and theta at age-14 prospectively predicted drinking at age-17 independent of one another. Among alcohol-naive individuals at age-14, attenuated P3 and theta increased the odds of new-onset alcohol behaviors 3 years later. Importantly, the endophenotypes provided significant incremental predictive power of future non-clinical alcohol use beyond relevant risk factors (prior alcohol use; tobacco/illicit drug initiation; parental alcohol use disorder).
The current report is the first of our knowledge to demonstrate that deviations in parietal P3 and midfrontal theta prospectively predict the emergence of normative/non-pathological drinking. P3 and theta provide modest yet significant explanatory variance beyond prominent self-report and familial risk measures. Findings offer strong evidence supporting the predictive utility of P3 and theta as candidate endophenotypes for adolescent drinking.
The History, Electrocardiogram (ECG), Age, Risk Factors, and Troponin (HEART) score is a decision aid designed to risk stratify emergency department (ED) patients with acute chest pain. It has been validated for ED use, but it has yet to be evaluated in a prehospital setting.
A prehospital modified HEART score can predict major adverse cardiac events (MACE) among undifferentiated chest pain patients transported to the ED.
A retrospective cohort study of patients with chest pain transported by two county-based Emergency Medical Service (EMS) agencies to a tertiary care center was conducted. Adults without ST-elevation myocardial infarction (STEMI) were included. Inter-facility transfers and those without a prehospital 12-lead ECG or an ED troponin measurement were excluded. Modified HEART scores were calculated by study investigators using a standardized data collection tool for each patient. All MACE (death, myocardial infarction [MI], or coronary revascularization) were determined by record review at 30 days. The sensitivity and negative predictive values (NPVs) for MACE at 30 days were calculated.
Over the study period, 794 patients met inclusion criteria. A MACE at 30 days was present in 10.7% (85/794) of patients with 12 deaths (1.5%), 66 MIs (8.3%), and 12 coronary revascularizations without MI (1.5%). The modified HEART score identified 33.2% (264/794) of patients as low risk. Among low-risk patients, 1.9% (5/264) had MACE (two MIs and three revascularizations without MI). The sensitivity and NPV for 30-day MACE was 94.1% (95% CI, 86.8-98.1) and 98.1% (95% CI, 95.6-99.4), respectively.
Prehospital modified HEART scores have a high NPV for MACE at 30 days. A study in which prehospital providers prospectively apply this decision aid is warranted.
The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.
Several of the prior chapters in this book allude to the work of Harold Garfinkel and his seminal Studies in Ethnomethodology (1967). One of the great lessons that one can take from that book is the idea that society is made up of people who “do” sociological theory or, rather, people who construct and deploy “lay-sociological theorizing” to both interpret and organize the world around them. Their everyday reasoning is a form of sociology Garfinkel would have us believe. Today, of course, the idea that people theorize in this sense, that they reason sociologically, has suffused itself throughout the discipline of sociology and its cognates. Take Michel De Certeau (1984), for example, or another sociologist of the quotidian, Henri Lefebrve (2004). Both argue that the social world is constructed, “enacted” through the deployment of interpretative skills and agency – through people's capacity to reason in particular ways. And consider other social sciences, such as anthropology. Here Tim Ingold (2011) argues that people construct their places of dwelling through conscious acts of “dialogic engagement”: they attend to, work with, and reflect on the things and persons around in ways that directs them in new trajectories, lines of action. All of this is a form of reasoning, Ingold claims.
The subtle differences between these various views notwithstanding, that people reason in a way that can be characterized as sociological, and that, as a result, the thing called society has the shape it has, is virtually commonplace in contemporary thinking. The word “theorizing,” however, has been ameliorated with alternate formulas by these (and other) authors. We have just listed some of the alternative words and phrases used: people enact their reasoning and they rationally engage their reasoning as part of how they produce dwellings. These and other formula stand as proxy for theorizing. One of the motivations for using alternatives is that many commentators, including those just mentioned, would appear to prefer keeping the term “theory” as a label for their own thinking rather than as one applicable to the non-professional arena. To put it directly, this move allows them to valorize what they do while giving lay persons’ actions a more prosaic, less consequential air.
The first starfish bed to be recognized from the Antilles is a lensoid body in the middle Miocene Grand Bay Formation of Carriacou, The Grenadines (West Indies). This unit was deposited in a turbidite basin in a region of active volcanism fed from one centre and preserves common deep-water taxa more typical of the Palaeozoic, such as crinoids and brachiopods. The starfish bed is a channel-fill deposit laid down in at least 150–200 m water depth, although the specimens may have been derived from shallower water. A goniasterid asteroid and an ophiacanthid ophiuroid have been recognized. The first articulated asteroid from the Antillean fossil record is Paragonaster(?) haldixoni sp. nov. In all skeletal features it appears close to the extant Atlantic species Paragonaster grandis H. L. Clark and P. subtilis (Perrier), but differs in having a single row of rectangular abactinal ossicles extending to the arm tip; these are longer than wide. The brittlestar, Ophiocamax ventosa sp. nov., is described on the basis of a fragmentary disc and arms from this deposit. The closest similarities are with the extant tropical western Atlantic species Ophiocamax hystrix Lyman and O. austera Verrill. However, the new species has thorns covering the entire surface of dorsal arm plates, while arm spines have a multitude of small thorns, loosely arranged in numerous rows and dorsal arm plate shape differs markedly. The occurrence of O. ventosa sp. nov. suggests that Ophiocamax has been a deep-sea taxon at least since the Miocene.
Measuring retouch location and intensity on hafted bifaces is shown to be an effective technique for assessing artifact function. Unlike other areas of North America, where dart technology is replaced by arrow technology, Coalition Period occupations on the Pajarito Plateau of New Mexico contain both hafted biface forms used simultaneously. A stylistic analysis of dart points shows that hafted biface forms found in Coalition Period contexts were recycled from Middle and Late Archaic surface scatters. Furthermore, retouch location and intensity show that Coalition Period dart points were used for cutting and sawing activities and not as projectile technology.
In the American Southwest, and throughout North America, dart-sized hafted bifaces identified as projectile points, normally associated with sites dating to the Paleoindian and Archaic time periods, are regularly found on sites dating to the past thousand years (cf. Kohler 2004; Turnbow 1997). Late period points were likely small and designed to be attached to the smaller arrow foreshaft. Although researchers have noted the presence of dart-sized points in settings where the bow and arrow were likely used, few have addressed the question of the context of manufacture or use of these larger hafted bifaces. In the Northern Rio Grande, the presence of Scottsbluff, Jay, Bajada, and other large dart points dating to the Late Paleoindian and Archaic in Coalition and Classic period sites rarely elicits more than a description as a “curated” item or “heirloom,” or as a knife replicating an older style.
Studies were conducted during a 2-yr period measuring corn silage and grain yield and velvetleaf seed production in response to velvetleaf density. Velvetleaf densities of 0, 2, 5, 10, and 21 plants/m2 were established in conventionally tilled corn. The percent corn yield reduction in response to velvetleaf density was similar for both years despite differences in total corn yield. Corn grain and silage yield responded differently to velvetleaf interference. Although both were adversely affected, silage yield reductions were twice that of grain at the low velvetleaf densities. A hyperbolic yield model predicted a maximum yield loss for corn silage and grain of 36 and 37% with incremental losses of 7 and 3%, respectively, as velvetleaf density increased. Velvetleaf seed production ranged from 2,256 to 4,844 seed/m2 from the lowest to the highest density. This study demonstrates that corn silage yield is more sensitive than corn grain yield to velvetleaf interference, as well as how crop value plays an important role in determining economic thresholds. Finally, this research confirms the prolific nature of velvetleaf and shows that even at low densities, velvetleaf seed production could affect weed control decisions for many seasons to come.
The aspect of Newton's Principia that has provoked the most controversy within the philosophy of science, other than his invocation of absolute space, time, and motion, has been his claim to have “deduced” the law of universal gravity from phenomena of orbital motion. In particular, a tradition that began with Pierre Duhem and continued with Karl Popper and then Imre Lakatos has argued that this claim is at best misleading (Duhem) and at worst a subterfuge (Lakatos). Among other reasons they have advanced against any such deduction is the objection that no deduction from consistent premises can yield a conclusion that entails one or more of these premises is false; yet one consequence of the law of universal gravity is that all the orbital phenomena from which Newton proceeds in his supposed deduction are, strictly, false. Duhem, Popper, and Lakatos insist, to the contrary, that only a hypothetico-deductive construal of Newton's evidence for universal gravity makes sense, Newton's outspoken objections to hypothetico-deductive evidence notwithstanding. More recently, Clark Glymour has offered a “bootstrapping” construal of Newton's evidence, proposing that it captures the logical force of the reasoning for universal gravitation in the Principia better than a straight-forward hypothetico-deductive construal can. Glymour too, however, sees no way around concluding that some of what Newton seems to think he is doing cannot be correct.
One issue this raises is understanding the reasoning Newton offers in arriving at the law of universal gravity and describes as a “deduction” from phenomena. Another is the extent to which such reasoning is cogent and illuminates scientific method. The simplest way to respond to these questions is to proceed step-by-step through Newton’s reasoning.
Temporal and spatial distribution of the chiton Acanthopleura japonica and associated molluscs were recorded on a semi-exposed tropical rocky shore in Hong Kong over 24 months. Most molluscs showed a clear vertical distribution pattern which varied with season. Many mobile gastropods, e.g. Monodonta labio, Cellana toreuma, Nerita albicilla and Thais clavigera, were found lower on the shore in summer (June–September), presumably as a response to the hot, desiccating conditions, but extended their range during winter (December–March). Acanthopleura, was distributed throughout the eulittoral and did not show such strong seasonal patterns, possibly due to the ability to use spatial refuges (specifically crevices) as a result of its flexible body-plan. Chitons exposed on horizontal rocks lost more body water during periods of emersion as compared to those in vertical or crevice habitats and, in summer, all animals on horizontal surfaces died. It is suggested that A. japonica uses cracks and crevices, which are not available to hard-shelled molluscs, throughout the year to reduce the impact of heat and desiccation stress during periods of emersion. This ability may explain the slight seasonal changes seen in Acanthopleura as compared to other species, and the dominance of chitons as herbivores on tropical shores.