OBJECTIVES/GOALS: Time restricted feeding (TRF) in diet induced obesity (DIO) has several health benefits, including improved metabolic rhythms and inflammation. Our lab has shown that TRF in DIO significantly reduces renal and aortic damage. The main goal of our research is to understand how TRF impacts aortic function, organ damage, and T cell activation in DIO. METHODS/STUDY POPULATION: We will use a 20-week DIO model, where mice will be on 20 weeks of normal fat diet (ND) or high fat diet (HFD). During weeks 18-20, mice will go through TRF intervention where food is restricted to the 12-hour active period or continue ad libitum feeding. At the end of the 2-week TRF intervention or continued ad libitum feeding, aortic stiffness will be measured via pulse wave velocity measurements. We will also collect kidney, aorta, and small intestine at the end of the 20-week protocol for flow cytometric analysis of tissue T cell activation as well as histological assessments. This will allow us to determine the relationship with organ damage, organ function, and the T cell response. We will also analyze tissue and circulating levels of inflammatory T cell-derived cytokines such as interleukin-17A (IL-17A) via ELISA. RESULTS/ANTICIPATED RESULTS: DIO mice showed significantly increased aortic stiffness (measured by pulse wave velocity) compared to mice on ND. Interestingly, TRF intervention in DIO mice reduced aortic stiffness compared to DIO ad libitum. Histological assessments also showed that TRF abolished aortic and kidney fibrosis suggesting a role for the timing of feeding in regulating aortic function and organ damage from chronic HFD. We have several ongoing experiments to determine the T cell response with TRF in DIO mice. We predict that TRF in DIO mice will significantly decrease inflammatory T cells and reduce cytokine abundance in target organs. DISCUSSION/SIGNIFICANCE: Our lab has shown that TRF reduces aortic thickness and aortic and kidney fibrosis, but the driving mechanisms are unknown. We propose that TRF reduces T cell activation in DIO mice leading to reduced organ damage. Our work will provide insight on how TRF in DIO regulates the T cell response and may improve inflammation in the kidney and aorta.

Strains with altered properties of host-induced modification (HIM) have been isolated. Someof these variants were stable on first isolation but the majority of them are unstable. They segregate during many generations two different stable HIM phenotypes and a third type which continues to segregate. Usually this instability disappears during repeated serial single colonyisolation, but in one case it still persisted after nine such single colony isolation steps. Evidence suggesting that they are unstable partial diploids is discussed.

In zygotes from matings between Hfr, F′ or F+ donors of E. coli K and F− recipients of E. coli B the restriction of λ. K and λ.C is 100 times less than in unmated B cells. This decrease in the capacity of zygotes to restrict phage λ is transient and is not related to the transfer of genes controlling host-induced modification during the cross.

The sites of mutations affecting host-controlled modification (HCM) have been mapped in E. coli K and E. coli B by conjugation and transduction experiments between mutants. These mutations all map close to the serB locus on the opposite side to the marker thr. Non-parental HCM has been observed among colonies obtained from Pl transduction experiments between HCM mutants. Control experiments have shown that these non-parental recombinants can not be accounted for by reversion of either parent and must result from recombination between mutants. Several genetic models are suggested which could account for these recombinants and an attempt is made to distinguish between various models by testing for complementation between mutants in a zygotic induction complementation test.

Transfer to slaughter may be very stressful for cattle and negatively affect their ultimate carcass pH. A potential link between farmers’ attitudes, farmers’ behaviour, responses of animals to handling and carcass pH in beef bull production was questioned. Whether carcass pH depends on experiences in handling and social mixing was analysed. We conducted a survey on commercial farms where we questioned farmers on their work and beliefs about bulls. Farmers’ behaviour with bulls during a test and bulls’ behaviour during loading in the truck for transport to the slaughterhouse were observed. The ultimate carcass pH was measured. Farmers tended to behave more gently with their bulls when they had positive attitudes towards gentle contacts with bulls (P = 0.07). The loading of bulls in the truck tended to be more difficult when the farmer was more ready to approach his bulls (P = 0.07). Carcass pH was higher for bulls that had not been transferred from a breeding to a finishing unit (P = 0.03). It tended to be higher when the farmer did not display a gentle behaviour (P = 0.09). The link between farmers’ attitudes and farmers’ behaviour and the lower meat pH resulting from a gentle farmers’ behaviour during finishing are consistent with previous findings in pig, veal or dairy productions. However, the present links were weaker than in the other productions, probably due to the low frequency of close contacts between farmers and beef bulls. When loading bulls into a truck, handlers use the tendency of animals to avoid people, hence overly positive behaviour with the animals during finishing may result in more difficulties at loading. In that case, use of alternative driving aids should be recommended. Our results on carcass pH suggest some habituation to transport among bulls transferred between breeding and finishing, even though the two experiences are several months apart. In view of our results, it seems that contacts with bulls, when they are needed, should be gentle.

New housing systems for commercial egg production, furnished cages and non-cage systems, should improve the welfare of laying hens. In particular, thanks to the presence of a litter area, these new housing systems are thought to satisfy the dust-bathing motivation of hens more than in conventional cages, in which no litter area is present. However, although apparently obvious, there is no concrete evidence that non-cage systems, particularly aviaries, satisfy hens' motivation to dust-bathe and thus improve hens' welfare in terms of dust-bathing behaviour. The aim of this study was to compare hens' dust-bathing motivation when housed for a long time under similar conditions to commercial conditions in laying aviaries (with litter) and in conventional cages (without litter). Three treatments were compared: hens reared in floor pens then housed in conventional cages, hens reared in furnished floor pens then housed in a laying aviary, and hens reared in rearing aviaries then housed in a laying aviary. All three treatments provided access to litter during the rearing period. After transfer to the laying systems, access to litter was maintained for the aviary hens but stopped for the cage hens. Twelve groups of four hens per treatment were tested 36 to 43 weeks after transfer. The hens were placed in sawdust-filled testing arenas, and latency to dust-bathe, duration and number of dust baths, and number of hens dust-bathing were recorded. Latency to dust-bathe was shorter, dust baths were longer and more numerous and more hens dust-bathed among cage hens than among aviary hens. Our results indicate that hens' motivation to dust-bathe was more satisfied in laying aviaries than in conventional cages. Thus, laying aviaries improve hens' welfare in term of dust-bathing behaviour compared with conventional cages.

In France, beef bulls are finished by breeder-finishers who produce calves and then fatten them, or by specialized finishers who fatten bulls that they buy. According to previous results on both dairy cows and pigs, breeding on the farm promotes positive attitudes of farmers towards animals, which can lead to improved animal health and growth. The mixing of bulls on their arrival at a specialized unit could stress them and thus impair health and growth. We hypothesized that breeder-finishers have more positive attitudes towards bulls and their work with bulls than specialized finishers, and that positive attitudes lead to better production, whereas mixing may be counterproductive. We observed 1038 bulls (67 groups) finished by breeder-finishers or specialized finishers in mixed and unmixed groups. Using a questionnaire, we assessed farmers' beliefs about the sensitivities of bulls, their attitude towards contacts with bulls, their beliefs about successful factors in finishing, and job satisfaction. We recorded the number of clinical signs and weight gain of the bulls. Specialized finishers tended to have more negative contacts with bulls than breeder-finishers ( P=0·06). Poor health of bulls was associated with (i) a positive attitude towards gentle contacts with bulls ( P<0·01), (ii) job satisfaction ( P=0·01), and (iii) was negatively correlated to beliefs in bulls being difficult animals ( P=0·09). Fast growth of bulls was associated with job satisfaction ( P<0·01). Unmixed bulls grew faster than mixed bulls ( P=0·05). We conclude that in finishing bulls, it is production results that have an impact on attitudes, rather than the opposite: the need for close contacts with bulls resulting from health problems engenders more positive attitudes of farmers towards their animals, and good production results increase job satisfaction. Variations in production results between breeder-finishers and specialized finishers seem to lie more in the fact that the latter always use animals mixed at the beginning of the finishing period - with mixing impairing growth - than in the attitudes of farmers towards animals and their work.

The mixed conducting LixMO2O4 system was shown to exhibit a high energy density (530Wh/kg) and average voltage (3.1V), suggesting that it would be a good candidate for a cathode in a Li-anode secondary battery. The transport properties of these oxide materials were then investigated by solid state 7Li NMR, dc and ac electrical measurements. The following phases are emphasized in this study: Li1.3MO204, Li2MO204, and the hydrated phase Li0.5 (H20) 1.3MO2O4.

The structural, chemical and electrochemical behavior of the layered molybdate oxides Na(Li)xMo2O4 have been investigated. We found a reversible sodium intercalation process over the range of composition 0.5 < x < 1.9 for the NaxMo2O4 system with 5 single phase domains at x = 0.55, 0.9, 1-1.4, 1.6, and 1.9. We took advantage of the high mobility of sodium diffusion in this compound to exchange sodium for lithium at relatively low temperature (300°C) and to prepare crystallographically pure LixMo2O4. Electrochemical data for the Li system shows that this material, which reversibly intercalates up to 1.7 Li atoms at an average potential of 3.1 volts, is a new promising cathode material for secondary lithium batteries. The ease with which these new molybdate phases can be intercalated is not limited to the alkali metals, since we also were able to intercalate H2O molecules.