Animal tissues are naturally 15N enriched relative to their diet and the extent of this difference (Δ15Nanimal-diet) has been correlated to the efficiency of N assimilation in different species. The rationale is that transamination and deamination enzymes, involved in amino acid metabolism are likely to preferentially convert amino groups containing 14N over 15N. However, in ruminants the contribution of rumen bacterial metabolism relative to animal tissues metabolism to naturally enrich animal proteins in terms of 15N has been not assessed yet. The objective of this study was to assess the impact of rumen and digestion processes on the relationship between Δ15Nanimal-diet and efficiency of N utilization for milk protein yield (milk N efficiency (MNE); milk N yield/N intake) as well as the relationship between the 15N natural abundance of rumen bacteria and the efficiency of N use at the rumen level. Solid- and liquid-associated rumen bacteria, duodenal digesta, feces and plasma proteins were obtained (n=16) from four lactating Holstein cows fed four different diets formulated at two metabolizable protein supplies (80% v. 110% of protein requirements) crossed by two different dietary energy source (diets rich in starch v. fiber). We measured the isotopic N fractionation between animal and diet (Δ15Nanimal-diet) in these different body pools. The Δ15Nanimal-diet was negatively correlated with MNE when measured in solid-associated rumen bacteria, duodenal digesta, feces and plasma proteins, with the strongest correlation found for the latter. However, our results showed a very weak 15N enrichment of duodenal digesta (Δ15Nduodenal digesta-diet mean value=0.42) compared with that observed in plasma proteins (Δ15Nplasma protein-diet mean value=2.41). These data support the idea that most of the isotopic N fractionation observed in ruminant proteins (Δ15Nplasma protein-diet) has a metabolic origin with very little direct impact of the overall digestion process on the existing relationship between Δ15Nplasma protein-diet and MNE. The 15N natural abundance of rumen bacteria was not related to either rumen N efficiency (microbial N/available N) or digestive N efficiency (metabolizable protein supply/CP intake), but showing a modest positive correlation with rumen ammonia concentration. When using diets not exceeding recommended protein levels, the contribution of rumen bacteria and digestion to the isotopic N fractionation between animal proteins and diet is low. In our conditions, most of the isotopic N fractionation (Δ15Nplasma protein-diet) could have a metabolic origin, but more studies are warranted to confirm this point with different diets and approaches.

For cancer prevention, the World Cancer Research Fund and American Institute for Cancer Research (WCRF/AICR) emphasise recommendations to improve individual behaviour, including avoidance of tobacco products, maintaining a lean body mass, participating in physical activity, consuming a plant-based diet, and minimising the consumption of energy-dense foods, such as sodas, red and processed meats and alcohol. In the present study of 275 healthy premenopausal women, we explored the association of adherence scores with levels of three biomarkers of antioxidant and inflammation status: serum C-reactive protein (CRP), serum γ-tocopherol and urinary F2-isoprostane. The statistical analysis applied linear regression across categories of adherence to WCRF/AICR recommendations. Overall, seventy-two women were classified as low ( ≤ 4), 150 as moderate (5–6), and fifty-three as high adherers ( ≥ 7). The unadjusted means for CRP were 2·7, 2·0 and 1·7 mg/l for low, moderate and high adherers (Ptrend= 0·03); this association was strengthened after adjustment for confounders (Ptrend= 0·006). The respective values for serum γ-tocopherol were 1·97, 1·63 and 1·45 μg/ml (Ptrend= 0·02 before and Ptrend= 0·03 after adjustment). Only for urinary F2-isoprostane, the lower values in high adherers (16·0, 14·5, and 13·3 ng/ml) did not reach statistical significance (Ptrend= 0·18). In an analysis by BMI, overweight and obese women had higher biomarker levels than normal weight women; the trend was significant for CRP (Ptrend< 0·001) and γ-tocopherol (Ptrend= 0·003) but not for F2-isoprostane (Ptrend= 0·14). These findings suggest that both adherence to the WCRF/AICR guidelines and normal BMI status are associated with lower levels of biomarkers that indicate oxidative stress and inflammation.

The effect of two feeding systems (indoors and at pasture) on intake and digestion of fresh grass was studied at two stages of regrowth (21 and 35 days of regrowth) in two parallel experiments. In Experiment 1, 10 adult Martinik rams weighing, on average, 50.5 (±0.9) kg, including four fitted with rumen cannula, were randomly allocated to two groups according to a 2 × 2 Latin Square design. These rams consumed a 21-day regrowth of Digitaria decumbens grass diet during two successive 28-day periods, indoors (five rams) or at pasture (five tethered rams). In Experiment 2, 10 other Martinik rams weighing, on average, 45.5 (±0.9) kg, including four fitted with rumen cannula, were randomly allocated to two groups according to a 2 × 2 Latin Square design. These rams consumed a 35-day regrowth of D. decumbens grass diet during two successive 28-day periods, either indoors (five rams) or at pasture (five tethered rams). For the indoors groups, in vivo organic matter digestibility (OMD) was measured by total collection of feces. In addition, OMD was estimated indoors and at pasture using the fecal CP (CPf) method (OMDCPf). Organic matter intake (OMI) was then estimated using OMDCPf and fecal organic matter output (OMICPf). Correlations of 0.49 and 0.77 were found between in vivo OMD and OMDCPf (P < 0.05) and between OMI and OMICPf (P < 0.001), respectively. OMDCPf was 1.8% (P < 0.05) and 2.7% (P < 0.01) lower indoors than at pasture at 21 and 35 days of regrowth, respectively, whereas OMICPf indoors was 1.1 and 1.16 times that registered at pasture at 21 and 35 days of regrowth, respectively. The higher OMDCPf at pasture was linked to the higher selective behavior of rams at pasture, whereas the differences in OMICPf between the two feeding systems were linked to differences in the total bulk density of the grass. These studies show that differences in OMDCPf and OMICPf exist between animals fed indoors and at pasture with the same forage and that these differences may vary according to the stage of regrowth of the grass offered.

In order to assess the diet of lactating ewes fed at pasture and the relationship of diet quality to pasture characteristics and milk production (MP), 12 lactating ewes were monitored during five lactation cycles (LCs). Individual faecal samples were collected three times per LC and scanned using a Foss NIRSystem 6500 monochromator. The organic matter digestibility (OMD), organic matter intake (OMI), digestible OMI (DOMI) and the chemical composition of the herbage ingested, i.e. the crude protein (CP) content of the herbage ingested (CPi) and the acid detergent fibre and lignin contents of the herbage ingested (ADFi and ADLi), were determined. The MP of the ewes and the pasture characteristics were measured and their relationships with diet quality were analysed.

OMI and DOMI were higher during the first and the fourth LC (P<0·01). OMD and CPi were higher during the second and the fifth LC (P<0·01). MP varied with OMI (P<0·01) and with DOMI (MP=0·1362×DOMI0·53, R2=0·40, P<0·001), whereas it was negatively correlated with OMD (r=−0·46, P<0·001). OMD and CPi were both positively correlated with the CP content of the pasture (r=0·25, P<0·03; r=0·50, P<0·001), whereas the ADFi was negatively correlated with CP content (r=−0·48, P<0·01). The variation in OMI, DOMI and MP, on the one hand, and OMD and CPi, on the other, throughout the different LCs illustrates the importance of measuring several parameters when evaluating diets at pasture.

TO all Mexico’s visitors, as to the United States’ beverage industry, “Tehuacán” is a trade-mark, a synonym for superlative mineral water. This product of some dozen bottling works at Tehuacán is justly regarded as the traveler’s health insurance in the tropics; it is, for its excellence, purchased in trainload lots by American brewers and soft-drink manufacturers. To sufferers from some exceedingly painful physical disorders the same word spells the relief obtainable from the “water cure” they take there. In pursuit of health, rest, and a superb climate for both, thousands from many nations annually make their way to the little spa “city” they find glistening in the highland sun against that masterpiece of natural sculpture, the Cerro Colorado, the advance line of Puebla’s mountain rampart against the deep tropics. Such are the facts that have realized Tehuacán’s modern fame and, thereby, prosperity.

Some twenty years after cortés consolidated the Conquest, New Spain experienced its most serious Indian uprising. This was the Mixtón War, which flared up unexpectedly in New Galicia during the rule of Mexico’s first and very celebrated Viceroy, Antonio de Mendoza. The immediate cause of the insurrection was the relapse into paganism of the chieftains of those tribes inhabiting the area surrounding Tlaltenango, situated inconveniently close to Guadalajara. Here the obnoxious rites of the pre-Conquest religions were suddenly re-established, and, before the Imperial Government at Mexico City awakened to the extent of this threat to the general peace, large numbers of tribesmen had been drawn into the dismaying retrogression and commenced violent aggressions against the colonists and the friendly Christian Indians of that section.

Charles Auguste marie Joseph Count de Forbin-Janson (1785–1844) had one of those rare natures whose essential spirit is that of the Christian apostle. That he was born to be a missionary is the only explanation of the single-minded, lifelong dedication of this greatly gifted nobleman whose apostolate included a dramatic and outstanding contribution to the mission record of the United States and Canada and who, although he did not die in America, was a martyr to his labor for its evangelization.

The room was rude and probably a little damp, because of the altitude and the prodigious rains sustained on the sierra, but it was also substantial, thick-walled in adobe and floored with the great rough bricks universally used in the period. Heavy, hand-hewn beams supported the weight of the sloping roof, made snug by countless overlapping tiles. The gloom of the rude chamber was candle-spotted, revealing, if dimly, its meagre but heavy furnishings; and a hearth fire must have contributed additional brightening, since it was nearing the very coldest season in the highlands, November. It was November 12 and approaching midnight in the Year of Grace, 1651.

It is Probable that no country outside the borders of the United States has, during the past half century, been more widely and more inaccurately presented by our American writers, than the Republic of Mexico. An examination of this surfeit of material and the multiplicity of its authors’ approaches to their topic discovers our Catholic neighborland to have long proved both an irresistible lure and an enigma to the professional producers of run-of-the-mill travel volumes as well as to the more popular (i.e., lighter-weight) theorists on economics and sociology. Their enthusiastic, even florid rhetoric has been ceaselessly inspired by the color and drama of Mexico; but otherwise their persistent output rarely gives much evidence of a clear understanding of Mexican attitudes or ideals and so, of competence to fathom the true significance of this nation’s turbulent history. Since the past cannot be overlooked in any safe estimate of the future, this is a regrettable fact that could prove most detrimental to that much-desired inter-American accord which has already cost the American taxpayer some millions of dollars. There are two easily understood reasons for such lack of insight on the part of so many of our writers; this has already served to rouse the resentment and disrespect of the Mexican reader of the American press while also resulting in a sincere acceptance by Anglo-Americans of a decidedly strange mixture of misinformation and absurdly ill advised opinion for “the truth about Mexico.”

A foreign reader of the North American press inevitably receives the impression that the majority of our feminine citizens are breadwinners if not actual career women, and that the much-noted independence and aggression of the American woman is, in a large measure, based on this fact—that she is economically self-sufficient or could be so if it should become necessary through a marriage wrecked by death or divorce, or desirable for any other reason. A glance at the statistics, however, immediately proves that a maximum of no more than 14 percent of our women are constantly employed outside the home, though it must be granted that a larger proportion has worked before marriage and presumably could do so again. In any case, the total in no wise approaches that which might be deduced from the amount of attention that the American working woman receives in the press and films which, supposedly, reflect the American scene.