Mitochondrial Respiration Is Decreased in Rat Kidney Following Fetal Exposure to a MaternalLow-ProteinDiet

Maternal protein restriction in rat pregnancy is associated with impaired renal development and age-related loss of renal function in the resulting offspring. Pregnant rats were fed either control or low-protein (LP) diets, and kidneys from their male offspring were collected at 4, 13, or 16 weeks of age. Mitochondrial state 3 and state 4 respiratory rates were decreased by a third in the LP exposed adults. The reduction in mitochondrial function was not explained by complex IV deficiency or altered expression of the complex I subunits that are typically associated with mitochondrial dysfunction. Similarly, there was no evidence that LP-exposure resulted in greater oxidative damage to the kidney, differential expression of ATP synthetase β-subunit, and ATP-ADP translocase 1. mRNA expression of uncoupling protein 2 was increased in adult rats exposed to LP in utero, but there was no evidence of differential expression at the protein level. Exposure to maternal undernutrition is associated with a decrease in mitochondrial respiration in kidneys of adult rats. In the absence of gross disturbances in respiratory chain protein expression, programming of coupling efficiency may explain the long-term impact of the maternal diet

Measuring Height Change Around the Periphery of the Greenland Ice Sheet With Radar Altimetry

This work is licensed under a Creative Commons Attribution 4.0 International License.Ice loss measurements around the periphery of the Greenland Ice Sheet can provide key information on the response to climate change. Here we use the excellent spatial and temporal coverage provided by the European Space Agency (ESA) CryoSat satellite, together with NASA airborne Operation IceBridge and automatic weather station data, to study the influence of changing conditions on the bias between the height estimated by the satellite radar altimeter and the ice sheet surface. Surface and near-surface conditions on the ice sheet periphery change with season and geographic position in a way that affects the returned altimeter waveform and can therefore affect the estimate of the surface height derived from the waveform. Notwithstanding the possibility of a varying bias between the derived and real surface, for the lower accumulation regions in the western and northern ice sheet periphery (<∼1 m snow accumulation yearly) we show that the CryoSat altimeter can measure height change throughout the year, including that associated with ice dynamics, summer melt and winter accumulation. Further, over the 9-year CryoSat lifetime it is also possible to relate height change to change in speed of large outlet glaciers, for example, there is significant height loss upstream of two branches of the Upernavik glacier in NW Greenland that increased in speed during this time, but much less height loss over a third branch that slowed in the same time period. In contrast to the west and north, winter snow accumulation in the south-east periphery can be 2–3 m and the average altimeter height for this area can decrease by up to 2 m during the fall and winter when the change in the surface elevation is much smaller. We show that vertical downward movement of the dense layer from the last summer melt, coupled with overlying dry snow, is responsible for the anomalous altimeter height change. However, it is still possible to estimate year-to-year height change measurements in this area by using data from the late-summer to early fall when surface returns dominate the altimeter signal

Strong contrast in mass and energy balance between a coastal mountain glacier and the Greenland ice sheet

We show a strong difference in surface mass and energy balance of a mountain glacier and two sites on the ice sheet at 64°N in West Greenland using stake and automated weather station observations. Net surface mass balance is on average 2.2 m w.e. less negative at the coast compared with the ice sheet in the same elevation. We find a larger energy turnover at the ice sheet margin on Qamanarssup Sermia than measured on the coastal mountain glacier Qassigiannguit with both energy input and output being of larger absolute value. More cloudiness and a thicker snow cover at the relatively humid coastal glacier result in smaller gains in net-shortwave radiation and smaller losses in net-longwave radiation and a less negative mass balance. Lower wind speeds at the coastal glacier result in weaker turbulent heat exchange between atmosphere and ice surface. On annual average, 17 W m−2 more energy is available for melt at the ice-sheet margin compared with the coastal glacier in the same elevation

Seismic characterization of a rapidly-rising jökulhlaup cycle at the A.P. Olsen Ice Cap, NE-Greenland

Rapidly-rising jökulhlaups, or glacial outburst floods, are a phenomenon with a high potential for damage. The initiation and propagation processes of a rapidly-rising jökulhlaup are still not fully understood. Seismic monitoring can contribute to an improved process understanding, but comprehensive long-term seismic monitoring campaigns capturing the dynamics of a rapidly-rising jökulhlaup have not been reported so far. To fill this gap, we installed a seismic network at the marginal, ice-dammed lake of the A.P. Olsen Ice Cap (APO) in NE-Greenland. Episodic outbursts from the lake cause flood waves in the Zackenberg river, characterized by a rapid discharge increase within a few hours. Our 6 months long seismic dataset comprises the whole fill-and-drain cycle of the ice-dammed lake in 2012 and includes one of the most destructive floods recorded so far for the Zackenberg river. Seismic event detection and localization reveals abundant surface crevassing and correlates with changes of the river discharge. Seismic interferometry suggests the existence of a thin basal sedimentary layer. We show that the ballistic part of the first surface waves can potentially be used to infer medium changes in both the ice body and the basal layer. Interpretation of time-lapse interferograms is challenged by a varying ambient noise source distribution.ISSN:0022-1430ISSN:1727-565

Cloud forcing of surface energy balance from in situ measurements in diverse mountain glacier environments

Clouds are an important component of the climate system, yet our understanding of how they directly and indirectly affect glacier melt in different climates is incomplete. Here we analyse high-quality datasets from 16 mountain glaciers in diverse climates around the globe to better understand how relationships between clouds and near-surface meteorology, radiation and surface energy balance vary. The seasonal cycle of cloud frequency varies markedly between mountain glacier sites. During the main melt season at each site, an increase in cloud cover is associated with increased vapour pressure and relative humidity, but relationships to wind speed are site specific. At colder sites (average near-surface air temperature in the melt season <0gg C), air temperature generally increases with increasing cloudiness, while for warmer sites (average near-surface air temperature in the melt season ≫0gg C), air temperature decreases with increasing cloudiness. At all sites, surface melt is more frequent in cloudy compared to clear-sky conditions. The proportion of melt from temperature-dependent energy fluxes (incoming longwave radiation, turbulent sensible heat and latent heat) also universally increases in cloudy conditions. However, cloud cover does not affect daily total melt in a universal way, with some sites showing increased melt energy during cloudy conditions and others decreased melt energy. The complex association of clouds with melt energy is not amenable to simple relationships due to many interacting physical processes (direct radiative forcing; surface albedo; and co-variance with temperature, humidity and wind) but is most closely related to the effect of clouds on net radiation. These results motivate the use of physics-based surface energy balance models for representing glacier-climate relationships in regional- and global-scale assessments of glacier response to climate change

A modified video-feedback intervention for carers of foster children aged 6 years and under with reactive attachment disorder : a feasibility study and pilot RCT

BACKGROUND: Looked-after children are at risk of suboptimal attachment patterns and reactive attachment disorder. However, access to interventions varies widely and there are no evidence-based interventions for this disorder. OBJECTIVES: (1) To adapt an existing video-feedback intervention to meet the specific needs of foster children in the UK with reactive attachment symptoms, (2) to conduct a case series to road-test the treatment manual and study procedures, (3) to conduct a scoping study of the key hurdles in a pilot trial and (4) to conduct a pilot randomised controlled trial of the adapted intervention to determine the feasibility of a future full-scale trial. DESIGN: This was a mixed-methods study. The adapted treatment manual was developed with expert input and tested on a small case series. Qualitative interviews with key stakeholders were used in the scoping study in preparation for the trial and later with foster carers who received the new intervention. The final stage was a feasibility and pilot randomised controlled trial of the new intervention, compared with usual care. Researchers assessing the outcomes were blinded to group assignment. SETTING: The study was set in outpatient child and adolescent mental health services and partner social services departments. Sites included urban and rural/semirural areas. PARTICIPANTS: Participants were foster carers with children aged ≤ 6 years presenting with difficulties in the domain of reactive attachment disorder. Key stakeholders included children's services managers and mental health service practitioners in the scoping study. Foster carers who received the modified intervention participated in qualitative interviews. INTERVENTION: The video-feedback intervention to promote positive parenting and sensitive discipline is an extensively evaluated and effective treatment approach. This intervention was modified (based on the adapted version for foster care in the Netherlands) to suit the needs of young children with reactive attachment symptoms in foster care in the UK and was delivered to improve the sensitive responding of foster carers, foster carer-child relationships and child outcomes. The modified intervention was delivered in-home by trained mental health professionals over a period of 4-6 months. MAIN OUTCOME MEASURE: The main outcome was reactive attachment symptom scores on the Disturbances of Attachment Interview. RESULTS: A series of minor changes to the intervention programme were introduced, which focused on improving its suitability for the UK foster care context. Challenges in recruitment meant that, despite numerous modifications to the protocol and the inclusion of additional sites, only 30 families (target, n = 40) were recruited to the randomised controlled trial (15 allocated to each group). However, most other trial parameters were deemed feasible and acceptable, particularly the high levels of data and treatment completeness. All randomised families were available for baseline analyses, but two in the treatment arm were not available for post-treatment analyses. The revised intervention was positively received by practitioners and foster carers. LIMITATIONS: Only three-quarters of the target sample size was recruited. Furthermore, the sites' own exclusion of potential participants and the low return rates of screening questionnaires raise the possibility of non-randomness of non-responses. CONCLUSION: A larger-scale trial may be feasible, but only if recruitment barriers can be overcome. Dedicated resources to support recruitment within local authorities and wider inclusion criteria are recommended. Central resourcing of intervention capacity to supplement NHS staff is also recommended. TRIAL REGISTRATION: This trial is registered as ISRCTN18374094. FUNDING: This project was funded by the National Institute for Health and Care Research ( NIHR ) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 35. See the NIHR Journals Library website for further project information

Cloud forcing of surface energy balance from in situ measurements in diverse mountain glacier environments

Clouds are an important component of the climate system, yet our understanding of how they directly and indirectly affect glacier melt in different climates is incomplete. Here we analyse high-quality datasets from 16 mountain glaciers in diverse climates around the globe to better understand how relationships between clouds and near-surface meteorology, radiation and surface energy balance vary. The seasonal cycle of cloud frequency varies markedly between mountain glacier sites. During the main melt season at each site, an increase in cloud cover is associated with increased vapour pressure and relative humidity, but relationships to wind speed are site specific. At colder sites (average near-surface air temperature in the melt season <0° C), air temperature generally increases with increasing cloudiness, while for warmer sites (average near-surface air temperature in the melt season ≫0° C), air temperature decreases with increasing cloudiness. At all sites, surface melt is more frequent in cloudy compared to clear-sky conditions. The proportion of melt from temperature-dependent energy fluxes (incoming longwave radiation, turbulent sensible heat and latent heat) also universally increases in cloudy conditions. However, cloud cover does not affect daily total melt in a universal way, with some sites showing increased melt energy during cloudy conditions and others decreased melt energy. The complex association of clouds with melt energy is not amenable to simple relationships due to many interacting physical processes (direct radiative forcing; surface albedo; and co-variance with temperature, humidity and wind) but is most closely related to the effect of clouds on net radiation. These results motivate the use of physics-based surface energy balance models for representing glacier-climate relationships in regional- and global-scale assessments of glacier response to climate change

Greenland ice sheet rainfall climatology, extremes and atmospheric river rapids

Greenland rainfall has come into focus as a climate change indicator and from a variety of emerging cryospheric impacts. This study first evaluates rainfall in five state-of-the-art numerical prediction systems (NPSs) (CARRA, ERA5, NHM-SMAP, RACMO, MAR) using in situ rainfall data from two regions spanning from land onto the ice sheet. The new EU Copernicus Climate Change Service (C3S) Arctic Regional ReAnalysis (CARRA), with a relatively fine (2.5 km) horizontal grid spacing and extensive within-model-domain observational initialization, has the lowest average bias and highest explained variance relative to the field data. ERA5 inland wet bias versus CARRA is consistent with the field data and other research and is presumably due to more ERA5 topographic smoothing. A CARRA climatology 1991–2021 has rainfall increasing by more than one-third for the ice sheet and its peripheral ice masses. CARRA and in situ data illuminate extreme (above 300 mm per day) local rainfall episodes. A detailed examination CARRA data reveals the interplay of mass conservation that splits flow around southern Greenland and condensational buoyancy generation that maintains along-flow updraft ‘rapids’ 2 km above sea level, which produce rain bands within an atmospheric river interacting with Greenland. CARRA resolves gravity wave oscillations that initiate as a result of buoyancy offshore, which then amplify from terrain-forced uplift. In a detailed case study, CARRA resolves orographic intensification of rainfall by up to a factor of four, which is consistent with the field data