Synthetic molecular machines hold tremendous potential to revolutionize chemical and materials sciences. Their autonomous motion controlled by external stimuli allows to develop smart materials whose ...properties can be adapted on command. For the realisation of more complex molecular machines, it is crucial to design building blocks whose properties can be controlled by multiple orthogonal stimuli. A major challenge is to reversibly switch from forward to backward and again forward light-driven rotary motion using external stimuli. Here we report a push-pull substituted photo-responsive overcrowded alkene whose function can be toggled between that of a unidirectional 2
generation rotary motor and a molecular switch depending on its protonation and the polarity of its environment. With its simplicity in design, easy preparation, outstanding stability and orthogonal control of distinct forward and backward motions, we believe that the present concept paves the way for creating more advanced molecular machines.
Peatlands contain one-third of soil carbon (C), mostly buried in deep, saturated anoxic zones (catotelm). The response of catotelm C to climate forcing is uncertain, because prior experiments have ...focused on surface warming. We show that deep peat heating of a 2 m-thick peat column results in an exponential increase in CH
emissions. However, this response is due solely to surface processes and not degradation of catotelm peat. Incubations show that only the top 20-30 cm of peat from experimental plots have higher CH
production rates at elevated temperatures. Radiocarbon analyses demonstrate that CH
and CO
are produced primarily from decomposition of surface-derived modern photosynthate, not catotelm C. There are no differences in microbial abundances, dissolved organic matter concentrations or degradative enzyme activities among treatments. These results suggest that although surface peat will respond to increasing temperature, the large reservoir of catotelm C is stable under current anoxic conditions.
The objective was to determine the effect of plasma progesterone concentration and the duration of proestrus during growth of the ovulatory follicle on fertility in beef cattle. Heifers (N = 61) and ...postpartum cows (N = 79) were assigned randomly to four groups in a two-by-two design involving luteal-phase versus subluteal-phase plasma progesterone concentrations and normal versus short proestrus. To synchronize follicular wave emergence, estradiol-17β was given im during the midluteal phase (Day 0) and concurrently, a once-used controlled intravaginal progesterone-releasing device was placed intravaginally. In the subluteal-phase progesterone groups, a luteolytic dose of PGF₂α was given on Day 0 and again 12 hours later. In the luteal-phase progesterone groups, PGF₂α was not given (so as to retain a functional CL). The controlled intravaginal progesterone-releasing device was removed and PGF₂α was given on Days 7 or 8 in the normal- and short-proestrus groups, respectively. Cattle were given lutropin im 12 or 36 hours later in the short- and normal-proestrus groups, respectively, with AI at 12 hours after lutropin treatment. Transrectal ultrasonography was used to monitor ovarian response during treatments and to diagnose pregnancy 60 days after AI. Cattle (heifers and cows combined) in the subluteal-phase progesterone groups and normal proestrus groups had a larger follicle at the time of AI, and a larger CL that secreted more progesterone 9 days after AI than cattle with luteal-phase progesterone concentrations or those with short proestrus (P < 0.03). There was a higher incidence of ovulation (P < 0.01) the day after AI in heifers (55/61; 90%) than in cows (44/79; 56%). Pregnancy rates ranged from 11% to 54%, and were higher in cattle (heifers and cows combined) in the subluteal-phase progesterone groups and normal proestrus groups than in the luteal-phase progesterone or short proestrus groups, respectively, (P < 0.02). In conclusion, a short proestrous interval reduced pregnancy rate after fixed-time AI in beef cattle. A low progesterone environment during growth of the ovulatory follicle increased the preovulatory follicle size and subsequent CL size and function, and compensated for the effect of a short proestrus on pregnancy rates.
To investigate the relationship between cerebral amyloid angiopathy (CAA), dementia, and cognitive function in an autopsy sample of 211 Japanese-American men from the population-based Honolulu-Asia ...Aging Study.
Starting in 1991, participants were assessed with the Cognitive Abilities Screening Instrument (CASI) and diagnosed with dementia (including subtype) based on published criteria. At autopsy, neuropathologists blinded to clinical data examined brains for neurofibrillary tangles (NFT), neuritic plaques (NP), and a number of vascular pathologies, including CAA. CAA was detected by immunostaining for betaA4 amyloid in parenchymal vessels in the neocortex and semiquantitatively rated. Linear regression models were used to examine the association of CASI score, dementia subtype, and CAA controlling for age at death, time between CASI administration and death, education, NP and NFT counts, infarcts, hemorrhage, and APOE genotype.
A total of 44.1% of subjects had CAA in at least one neocortical area. The presence of CAA was associated with higher mean NFT and NP counts and having at least one APOE-epsilon4 allele. The interaction between CAA and AD on the adjusted mean CASI score was significant; compared with nondemented men without CAA, the CASI score was 16.6% lower in men with AD and no CAA and 45.9% lower in men with AD plus CAA.
CAA may contribute to the clinical presentation of dementia by interacting with other neuronal pathologies, leading to more severe cognitive impairment in men with both CAA and AD compared with men with only AD or CAA.
The aims of this study were (1) to establish an optimal cut-off point for evaluating the effect of the preovulatory follicle (POF) diameter in timed AI (TAI) programs, and (2) to evaluate the effect ...of postponing TAI in cows with smaller follicles on pregnancy per AI (P/AI). In Study 1, Nelore cows (n = 426) were subjected to an estradiol-progesterone (P4) based TAI protocol. The diameter of POF was measured at TAI, 48 h after P4 insert removal. From the ROC curves for determining the relationship between the POF diameter and pregnancy, the cut-off was 11 mm (P < 0.001). Cows with larger POF had greater (P < 0.05) P/AI (62.5%) than cows with smaller POF (34.8%). In Study 2, Nelore cows (n = 1257) were subjected to the same TAI protocol as in Study 1. Before TAI, cows were separated according to POF diameter in three groups: (1) Larger POF (LP, n = 873; POF ≥11 mm), (2) Smaller POF 0 h (SP0, n = 195; POF <11 mm), and (3) Smaller POF 24 h (SP24, n = 189; POF <11 mm). Cows in the LP and SP0 were TAI at 48 h and cows in the SP24 group were TAI at 72 h after P4 insert removal. Cows in the LP group had the greatest (P < 0.05) P/AI (60.25%), followed by cows in the SP24 group (41.8%), while cows in the SP0 group had the lowest P/AI (31.8%). In conclusion, cows with smaller follicles have lower P/AI, but postponing the TAI by 24 h in these cows increases P/AI.
•Postponing the TAI by 24 h in cows with smaller follicles increases P/AI.•Cows with preovulatory follicle of ≥11 mm diameter have greater P/AI.•Multiparous had larger POF and greater P/AI than primiparous cows.
The objective of this study was to determine the effects of low versus physiologic plasma progesterone concentrations during the ovulatory wave on fertility in cattle. Suckled beef cows (
Bos taurus; ...n
=
129) and pubertal heifers (
Bos taurus; n
=
150) at random stages of the estrous cycle were given a luteolytic dose of prostaglandin F
2α (500
μg cloprostenol; PGF) twice, 11 d apart. Ten days after the second PGF treatment, cattle were given estradiol benzoate im (1.5 and 1.0
mg for cows and heifers, respectively) and a progesterone-releasing intravaginal device (Cue-Mate) with a single pod containing 0.78
g progesterone (Day 0). Cattle in the low-progesterone group (n = 148) received a luteolytic dose of PGF on Day 0, whereas those in the high-progesterone (i.e., physiologic plasma concentrations) group (n
=
131) were allowed to retain their corpora lutea. On Day 8, the Cue-Mate was removed, and PGF was given to both groups. Fifty-four hours to 56
h later, cattle received 12.5
mg of porcine LH (pLH) im and were concurrently artificially inseminated. The dominant follicle in the low-progesterone group was larger (P
<
0.001) than that in the high-progesterone group on the day of insemination (14.9
±
0.3
mm vs. 12.7
±
0.3
mm, mean
±
SEM). At 7 d after ovulation, the low-progesterone group had a larger corpus luteum (24.5
±
0.54
mm vs. 21.9
±
0.64
mm, P
<
0.01) and higher plasma progesterone concentration (4.0
±
0.3 vs. 3.1
±
0.2, P
<
0.01) than that of the high-progesterone group. However, pregnancy rates did not differ (79 of 148, 53.4%, and 70 of 131, 53.4%) for low- and high-progesterone groups, respectively). In summary, low circulating progesterone concentrations during the growing phase of the ovulatory follicle resulted in a larger dominant follicle and a larger CL that produced more progesterone, with no significant effect on pregnancy rate.
The aim of this study was to evaluate whether changing the interval from CIDR removal to timed artificial insemination (TAI) according to the diameter of the preovulatory follicle (POF) would improve ...pregnancy per AI in cows. In Study 1, a retrospective analysis of TAI experiments (n=96 cows) was performed to characterize the time of ovulation according to the diameter of the dominant follicle. It was observed that cows with a larger POF had ovulations earlier than cows with smaller POF, according to the equation: y=0.72x2−26.74x+264.54 (R2=0.63; P<0.001). In Study 2, lactating Nelore cows (n=412) were subjected to an EB-CIDR based TAI protocol. On the morning of Day 10 (time of TAI), cows were randomized into Control (n=209) and Block (n=203) groups; (1) Cows in the Control Group were TAI 48h after CIDR removal (08:00am on Day 10), and; (2) Cows in the block group were inseminated once at one of the following time points, according to the diameter of the POF on Day 10: B0 (POF≥15mm, TAI 0h after convetional TAI), B1 (POF 13–14.9mm, TAI 6h later), B2 (POF 10.1–12.9mm, TAI 24h later) and B3 (POF≤10mm, TAI 30h later). The cows of the Block Group had greater pregnancy rates per AI than the Control Group (129/203, 63.5% when compared with 102/209, 48.8%, respectively; P<0.01). In conclusion, results of the present study demonstrate that adjusting the timing of TAI according to the diameter of the POF can be an effective practice for improving fertility of cows in TAI protocols.
The aim of this study was to evaluate if prostaglandin F2α (PGF) can be used to induce ovulation in a GnRH-progesterone based protocol. In Experiment 1 crossbred dairy cows (n=32) were synchronized ...with a progesterone-GnRH based protocol for seven days, where the luteolytic dose of 150μg PGF was given 24h prior progesterone device removal (CIDR). On Day 8 cows were separated into two groups to receive: 1) 2mL of Saline (Control Group, n=15) or 2) 150μg of PGF (PGF Group, n=17). Ovulation rate was higher in the PGF than Control group (100% vs 53.3%, P=0.001, Odds ratio=30.88). The percentage of cows that ovulated synchronously tended to be higher in the PGF than Control group (P=0.1, Odds ratio=9.6). Experiment 2 was performed in a cross-over (3×3) design. Crossbred dairy cows (n=25) received a CIDR for seven days and GnRH on Day 0. Seven days later 150μg of PGF was given and the progesterone device was removed, and 24h later cows were distributed into three groups to receive: 1) 2mL of Saline (Control Group, n=25), 2) 150μg of PGF (PGF Group, n=25) or 3) 1mg of ECP (ECP Group, n=23). Diameter of ovulatory follicle was larger in the PGF and Control than ECP Group (P=0.002, Effect size>4.0). Synchronized ovulation rate (between 72 and 96h after CIDR removal) tended to be higher in PGF group in Control group (P=0.1, Odds ratio=0.35). Results suggest that PGF is equally efficient to ECP to induce synchronized ovulation in dairy cows subjected to progesterone-GnRH based protocols.
•The effect of prostaglandin F2α (PGF) as ovulation inducer in a GnRH-progesterone based protocol was evaluate.•PGF was compared with estradiol cypionate in a protocol to cattle.•PGF is equally efficient to ECP to induce concentrated ovulation in dairy cows.
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