We introduce a model system of anisotropic colloidal 'rocks'. Due to their shape, the bonding introduced via non-absorbing polymers is profoundly different from spherical particles: bonds between rocks are rigid against rotation, leading to strong frustration. We develop a geometric model which captures the essence of the rocks. Experiments and simulations show that the colloid geometry leads to structures of low fractal dimension. This is in stark contrast to gels of spheres, whose rigidity results from locally dense regions. At high density the rocks form a quasi one-component glass. PACS numbers: 82.70.Dd;64.60.Cn Dispersions of mesoscopic colloidal particles are important for several reasons. They model atomic and molecular systems, yet single particle level imaging reveals local phenomena, such as pinpointing mechanisms of dynamic arrest [1,2], which are inaccessible in conventional systems. Furthermore, colloidal and nanoparticle systems are important materials. Colloidal gels stabilize a range of industrial and consumer products from pesticides to cosmetics. Underlying both is the tuneability of interactions between colloids which are theoretically well understood and hence enable design of self-assembled structures at small lengthscales. Recently, anisotropic interactions using a number of sticky patches per particle have been introduced, opening new routes of self-assembly. Reducing the number of patches per particle leads to networks of low fractal dimension [3].Here we consider depletion induced gels of anisotropic particles. The addition of polymer mediates an effective attraction between the colloids due to excluded volume effects -see Fig 1(b). The depth of this attraction is proportional to the polymer concentration c p and the range is set by the polymer size. At sufficient strengths of the depletion attraction, spinodal phase separation leads to colloid-rich (polymer-poor) 'colloidal liquid' and colloidpoor (polymer-rich) 'colloidal gas' phases. Decreasing the range of the depletion interaction by reducing the size of the polymer relative to the colloid leads to a higher density colloidal liquid. If the packing fraction of the colloidal liquid is high enough (φ ≈ 0.58) phase separation is arrested. The resulting network of voids combined with 'arms' of high local colloid density, is termed a gel [4].A range of anisotropic particles has been synthesized [5,6], and systems with hard interactions have recieved considerable attention very recently: rods form the expected liquid crystalline phases [7], anisotropy suppresses long-ranged order close to a wall [8] and at high density, colloidal dumbells show multiple relaxation pathways [9]. However, although networks of anisotropic particles are important, e.g. in shiny paper coatings, systematic experimental studies of the effect of anisotropy in systems with attractions are limited: attractions between colloidal platelets can lead to stacking [10,11], gels of colloidal rods form bundles [12] and due to their patchy interactions, clay platelets for...

Background Weight loss, hyperglycaemia and diabetes are known features of pancreatic cancer. We quantified the timing and the amount of changes in body mass index (BMI) and glycated haemoglobin (HbA1c), and their association with pancreatic cancer from five years before diagnosis. Methods A matched case-control study was undertaken within 590 primary care practices in England, United Kingdom. 8,777 patients diagnosed with pancreatic cancer (cases) between 1st January 2007 and 31st August 2020 were matched to 34,979 controls by age, gender and diabetes. Longitudinal trends in BMI and HbA1c were visualised. Odds ratios adjusted for demographic and lifestyle factors (aOR) and 95% confidence intervals (CI) were calculated with conditional logistic regression. Subgroup analyses were undertaken according to the diabetes status. Results Changes in BMI and HbA1c observed for cases on longitudinal plots started one and two years (respectively) before diagnosis. In the year before diagnosis, a 1 kg/m2 decrease in BMI between cases and controls was associated with aOR for pancreatic cancer of 1.05 (95% CI 1.05 to 1.06), and a 1 mmol/mol increase in HbA1c was associated with aOR of 1.06 (1.06 to 1.07). ORs remained statistically significant (p < 0.001) for 2 years before pancreatic cancer diagnosis for BMI and 3 years for HbA1c. Subgroup analysis revealed that the decrease in BMI was associated with a higher pancreatic cancer risk for people with diabetes than for people without (aORs 1.08, 1.06 to 1.09 versus 1.04, 1.03 to 1.05), but the increase in HbA1c was associated with a higher risk for people without diabetes than for people with diabetes (aORs 1.09, 1.07 to 1.11 versus 1.04, 1.03 to 1.04). Conclusions The statistically significant changes in weight and glycaemic control started three years before pancreatic cancer diagnosis but varied according to the diabetes status. The information from this study could be used to detect pancreatic cancer earlier than is currently achieved. However, regular BMI and HbA1c measurements are required to facilitate future research and implementation in clinical practice.

This paper describes and interprets the floodplain stratigraphy of two low-energy rivers in the East Midlands, U.K. and goes on to present an appropriate model of floodplain evolution that may be applicable to other lowland rivers in temperate mid-latitudes. Work has been undertaken at the reach level to try and characterize the entire system. In general only laterally extensive exposures have been used, and detailed stratigraphic and microstratigraphic recording has been used to facilitate process interpretations. All the sites have been radiocarbon dated. The dataset consists of three sites in the Soar valley and five sites in the larger Nene valley. The most common sedimentary architecture is a basal gravel with occasional shallow channels, covered by a mixed loam (sand-silt-clay) of variable thickness with landsurfaces and evidence of bioturbation. This loam is frequently interrupted by palaeochannels, and finally all these sediments are buried by a massive silt-clay unit. Most of the palaeochannels were abandoned in the early Flandrian, or between ca. 3500 years BP and 2000 years BP. The superficial silty clay is diachronous largely because of the irregular topography of the floodplain onto which it was deposited; dates from non-palaeochannel sections range from ca. 3500 BP to ca. 2100 years BP. The floodplain stratigraphy has been profoundly influenced by soil development and sub-aerial processes, especially tree-throw, which has produced distinctive sedimentary structures. The loam unit is interpreted as a soil which developed inbetween both silting palaeochannels and active channels. The landsurfaces are both earlier and contemporaneous with the later phase of channel abandonment. There is some evidence, ca . 5000-4000 BP, of a rise in floodplain watertables. An evolutionary model is proposed which can account for the stratigraphic evidence reported here. It is based upon the development of an anastomosing (stable multiple-channel) system from an initial braided-river topography and its eventual conversion to a predominantly single-channel system due to floodplain and channel siltation. The reduction of channels is compensated for by a change in channel types and capacities while the floodplain aggrades; this is the stable-bed aggrading-banks (SBAB) model, which necessitates no changes in discharges. It is suggested that the sub-meandering or straight to sinuous nature of many lowland U.K. channels may be due to their evolution from an anastomosing pattern where the least meandering channels survived typically with a box-S shape planform and at the edges of the floodplain. The sites also show that the Lateglacial fluvial history of the two catchments seems to have been very different, with incision and subsequent aggradation occurring during the Younger Dryas in the Nene but not in the Soar. Given the proximity and similarity of the two catchments this suggests that relatively minor local factors may have been able to push some catchments across fluvial thresholds. In contrast the Flandrian history of the two rivers has been broadly similar, although there is evidence of greater lateral instability and floodplain reworking in the Soar which may be due to hydrogeological factors or a different landuse history. This work strongly suggests that new process-based interpretations of floodplain stratigraphy, and new models of floodplain evolution may be required before alluvial history can be easily related to the changing Lateglacial and Flandrian climate of lowland U.K.

The present paper provides a contribution to the study of the glacial history of Angus, a subject which has been sadly neglected during the last hundred years. A detailed description of the glacial deposits in the Lunan and Brothock valleys is given, and it is concluded that the last ice sheet to occupy the area advanced after the " 100-foot" marine incursion. This ice advance is tentatively correlated with the Aberdeen advance described by Synge and the Perth advance described by J. B. Simpson.

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