Stability and Change in Sexual Orientation and Genital Arousal over Time

Longitudinal work suggests that sexual orientation can change over time in men and women. These studies, however, may be susceptible to the bias of self-report. The current study therefore examined self-reported sexual orientation in addition to an objective correlate: genital arousal to erotic videos showing males or females. For 52 men (19 heterosexual, 19 bisexual, 14 homosexual) and 67 women (31 heterosexual, 18 bisexual, 18 homosexual), these measures were taken twice, with approximately 1 year between sessions. For self-reported sexual orientation, women reported lower relative stability (weaker correlation) than men over time, even though women did not change more overall (no stronger mean difference) than men between sessions. Bisexual individuals reported lower relative stability and more mean change than heterosexual and homosexual individuals. For genital arousal, across all groups, response patterns were correlated over time to a similar extent and showed little difference between sessions. Moreover, change in self-reported sexual orientation did not correspond with the change in genital arousal, regardless of sex. Perhaps self-reports overestimate changes in sexual orientation, since these changes were not reflected in physiological sexual response.

Sex Differences in Sexual Arousal and Finger Length Ratio

Most men show sexual arousal to one, preferred sex, whereas most women respond to both sexes, regardless of their sexual orientation. A different research program indicates that men have lower second-to-fourth finger length ratios (2D:4D) than women, possibly because men are exposed to higher levels of androgens during prenatal development. We hypothesized that sex differences in sexual arousal patterns are influenced by prenatal androgen exposure and would thus be explained by sex differences in 2D:4D. We measured the sexual response patterns of 139 men and 179 women via genital arousal and pupil dilation to erotic videos, in addition to their 2D:4D. Compared to women, men showed stronger responses to one sex over the other, although this pattern was clearer in genital arousal than pupil dilation. Men also had lower 2D:4D than women. However, there was no evidence that sex differences in sexual arousal related to sex differences in 2D:4D. Thus, whichever factor explains sex differences in sexual arousal patterns may not be reflected in 2D:4D.

Sexual Orientation, Sexual Arousal, and Finger Length Ratios in Women

In general, women show physiological sexual arousal to both sexes. However, compared with heterosexual women, homosexual women are more aroused to their preferred sex, a pattern typically found in men. We hypothesized that homosexual women's male-typical arousal is due to their sex-atypical masculinization during prenatal development. We measured the sexual responses of 199 women (including 67 homosexual women) via their genital arousal and pupil dilation to female and male sexual stimuli. Our main marker of masculinization was the ratio of the index to ring finger, which we expected to be lower (a masculine pattern) in homosexual women due to increased levels of prenatal androgens. We further measured observer- and self-ratings of psychological masculinity-femininity as possible proxies of prenatal androgenization. Homosexual women responded more strongly to female stimuli than male stimuli and therefore had more male-typical sexual responses than heterosexual women. However, they did not have more male-typical digit ratios, even though this difference became stronger if analyses were restricted to white participants. Still, variation in women's digit ratios did not account for the link between their sexual orientation and their male-typical sexual responses. Furthermore, homosexual women reported and displayed more masculinity than heterosexual women, but their masculinity was not associated with their male-typical sexual arousal. Thus, women's sexual and behavioral traits, and potential anatomical traits, are possibly masculinized at different stages of gestation.

Patterns of Genital Sexual Arousal in Transgender Men

Most men show genital sexual arousal to one preferred gender. Most women show genital arousal to both genders, regardless of their sexual preferences. There is limited knowledge of whether this difference is driven by biological sex or gender identity. Transgender individuals, whose birth sex and gender identity are incongruent, provide a unique opportunity to address this question. We tested whether the genital responses of 25 (female-to-male) transgender men followed their female birth sex or male gender identity. Depending on their surgical status, arousal was assessed with penile gauges or vaginal plethysmographs. Transgender men's sexual arousal showed both male-typical and female-typical patterns. Across measures, they responded more strongly to their preferred gender than to the other gender, similar to (but not entirely like) 145 cisgender (nontransgender) men. However, they still responded to both genders, similar to 178 cisgender women. In birth-assigned women, both gender identity and biological sex may influence sexual-arousal patterns.

Gender Nonconformity of Bisexual Men and Women

The degree to which bisexual-identified individuals are distinct from either heterosexual or homosexual individuals in their sexual orientation is an ongoing debate. We examined potential differences between these groups with respect to a strong correlate of sexual orientation, gender nonconformity (femininity in males, masculinity in females). Across pooled data, we compared self-reports of childhood gender nonconformity (n = 919) and adulthood gender nonconformity (n = 1265) and observer ratings of adulthood gender nonconformity (n = 915) between sexual orientations. Most analyses suggested a steady increase in gender nonconformity from exclusively heterosexual to exclusively homosexual. However, in some analyses, bisexual men were closer to homosexual men than to heterosexual men in their gender nonconformity. The intermediate status of bisexual people in gender nonconformity was not due to the sample having a mixture of very gender-conforming and very gender-nonconforming individuals. In total, men and women with bisexual orientations appeared neither like heterosexual nor homosexual individuals, at least with respect to their gender-related traits.

Gender Nonconformity of Identical Twins with Discordant Sexual Orientations: Evidence from Video Recordings

Gender nonconformity (femininity in males, masculinity in females) is more common in non-heterosexual (bisexual and homosexual) than heterosexual individuals. In the past research (Watts, Holmes, Raines, Orbell, & Rieger, 2018b), identical twins discordant for sexual orientation were perceived more similar in their gender nonconformity than unrelated heterosexual and non-heterosexual people. Yet, these perceptions were based on photographs, which do not contain all aspects of gender nonconformity, such as movement and sound. This could have led to an underestimation of observable difference within twin pairs. We examined evaluations of video recordings from adult identical twins with discordant sexual orientations (eight male pairs, 11 female pairs). These twins were a small subset of those who participated in Watts et al. (2018b). Non-heterosexual twins were rated as significantly more gender nonconforming than their heterosexual co-twins, but only when males and females were combined. Their difference was smaller than the analogous difference between identical twins who were concordant heterosexual (three male pairs, three female pairs) and, unrelated to them, identical twins who were concordant non-heterosexual (six male pairs, two female pairs). These patterns were partially confirmed with twins' self-reported gender nonconformity. Shared influences possibly made twins from discordant pairs somewhat similar in their gender nonconformity, even if non-shared factors differentiated their sexual orientations.

Robust evidence for bisexual orientation among men

The question whether some men have a bisexual orientation-that is, whether they are substantially sexually aroused and attracted to both sexes-has remained controversial among both scientists and laypersons. Skeptics believe that male sexual orientation can only be homosexual or heterosexual, and that bisexual identification reflects nonsexual concerns, such as a desire to deemphasize homosexuality. Although most bisexual-identified men report that they are attracted to both men and women, self-report data cannot refute these claims. Patterns of physiological (genital) arousal to male and female erotic stimuli can provide compelling evidence for male sexual orientation. (In contrast, most women provide similar physiological responses to male and female stimuli.) We investigated whether men who self-report bisexual feelings tend to produce bisexual arousal patterns. Prior studies of this issue have been small, used potentially invalid statistical tests, and produced inconsistent findings. We combined nearly all previously published data (from eight previous studies in the United States, United Kingdom, and Canada), yielding a sample of 474 to 588 men (depending on analysis). All participants were cisgender males. Highly robust results showed that bisexual-identified men's genital and subjective arousal patterns were more bisexual than were those who identified as exclusively heterosexual or homosexual. These findings support the view that male sexual orientation contains a range, from heterosexuality, to bisexuality, to homosexuality.

Metals and marine microplastics: Adsorption from the environment versus addition during manufacture, exemplified with lead

There are two means by which metals associate with microplastics in the aquatic environment. Firstly, they may be adsorbed to the plastic surface or hydrogenous-biogenic accumulations thereon, and secondly, they may be present in the polymeric matrix as functional additives or as reaction or recyclate residues. In this study, the relative significance of these associations is evaluated with respect to Pb in beached marine microplastics. Thus, adsorbed Pb was determined in <5 mm, neutrally-coloured polyethylene pellets that contained no detectable Pb added during manufacture by digestion in dilute aqua regia, while the bioaccessibility of this association was evaluated using an avian physiologically-based extraction test (PBET). Here, up to about 0.1 μg g^-1 of Pb was adsorbed to the plastic and between about 60 and 70% of the metal was accessible. Lead present as additive or residue was determined by x-ray fluorescence analysis of a wider range of beached plastics (polyolefins and polyvinyl chloride), with a selection of positive samples grated to mm-dimensions and subjected to the PBET. Here, total Pb concentrations up to 40,000 μg g^-1 and bioaccessibilities up to 16% were observed, with bioaccessible concentrations exceeding equivalent values for adsorbed Pb by several orders of magnitude. Ingestive exposure to Pb, and potentially other toxic metals, is more important through the presence of additives in historical plastics and recyclate residues in contemporary plastics than from adsorption, and it is recommended that future studies focus more on the environmental impacts and fate of metals bound in this form.

Bisexual men with bisexual and monosexual genital arousal patterns

Some research suggests that bisexual-identified men show bisexual genital arousal, whereas other research indicates monosexual arousal: they are aroused to one sex only. These seemingly contradictory findings may be due to the type of men identifying as bisexual and the performed analyses. We examined whether both bisexual and monosexual arousal patterns could co-occur within the same sample. 114 men of different sexual orientations viewed erotic videos of males or females while their penile circumference was measured. On average, bisexual-identified men were more aroused to males than females, and especially if they identified as "bisexual leaning gay." However, also on average, bisexual men showed bisexual arousal, and especially if they were "bisexual leaning straight". Furthermore, there was more variability in the arousal patterns of bisexual-identified men, compared with other men. Based on their physiological sexual arousal, bisexual men appear to be a more diverse group than men who identified as heterosexual or homosexual.

Correction to: Finger Length Ratios of Identical Twins with Discordant Sexual Orientations

Readers should note that the confidence intervals for the effect of sexual orientation on 2D:4D in the left hand of female twins are incorrectly reported in Table 1 of this article. In particular, the upper limit of the confidence intervals is missing a minus sign.

Finger Length Ratios of Identical Twins with Discordant Sexual Orientations

A proposed marker of prenatal androgen exposure is the ratio of the index finger to ring finger (2D:4D). Within each sex, this ratio may be lower for those who were exposed to higher levels of androgens and become attracted to women, as compared to those who were exposed to lower levels of androgens and become attracted to men. We examined these patterns in identical twins with discordant sexual orientations. Because these twins are genetically identical, differences in prenatal androgen exposure, as reflected in their different finger length ratios, might contribute to their discordance. For 18 female twin pairs, non-straight (bisexual or lesbian) twins had significantly lower, or more masculinized, 2D:4D ratios than their straight co-twins, but only in the left hand. For 14 male pairs, non-straight twins had, contrary to our prediction, more masculinized finger length ratios than straight co-twins, but this difference was not significant. A reanalysis of present and previous data (Hall & Love, 2003; Hiraishi, Sasaki, Shikishima, & Ando, 2012) suggested that these patterns were robust. Furthermore, males had more masculinized 2D:4D ratios than females. This sex difference did not vary by sexual orientation.

Sexual Arousal Patterns of Identical Twins with Discordant Sexual Orientations

Genetically identical twins can differ in their self-reported sexual orientations. However, whether the twins' subjective reports reflect valid differences in their sexual orientations is unknown. Measures of sexual orientation, which are free of the limitations of self-report, include genital arousal and pupil dilation while viewing sexual stimuli depicting men or women. We examined these responses in 6 male twin pairs and 9 female twin pairs who reported discordant sexual orientations. Across measures, heterosexual male twins responded more strongly to women than to men. Their homosexual co-twins showed an opposite pattern. Heterosexual female twins responded equally to both sexes, whereas their homosexual co-twins responded somewhat more to women than men. These differences within pairs were similar to differences between unrelated heterosexual and homosexual males and females. Our study provides physiological evidence confirming twins' discordant sexual orientations, thereby supporting the importance of the non-shared environment for the development of sexual orientation and sexual arousal.

Unequal Cumulative Incidence and Mortality Outcome in Childhood Brain and Central Nervous System Malignancy in the USA

BACKGROUND

While survival in overall pediatric malignancy has improved during recent decades, brain/central nervous system (CNS) tumors has not demonstrated comparable survival advantage. Incidence and mortality data in this malignancy continue to illustrate race and sex differences; however, there are few data in the pediatric setting. This study sought to characterize brain/CNS tumors by socio-demographic and assess racial and sex variances in both cumulative incidence and mortality.

METHODS

A retrospective cohort design with Surveillance, Epidemiology and End Results (SEER) 1973-2014 was used for the assessment of children aged < 1-19 years diagnosed with brain/CNS tumors. The age-adjusted incidence rates were used for temporal trends, percent change, and annual percent change. We utilized binomial regression model to determine the exposure effect of race and sex on cancer mortality, adjusting for potential confounders.

RESULTS

Childhood brain/CNS tumor cumulative incidence (CmI) continues to rise in annual percent change, and mortality varied by race, sex, and year of diagnosis. The CmI was highest among whites, intermediate among blacks, and lowest among Asians, as well as lower in females relative to that in males. Compared to whites, blacks were 21% more likely to die from brain/CNS tumors [risk ratio (RR) 1.21, 95% confidence interval (C.I.) 1.13-1.28], while males were 4% more likely to die relative to females (RR 1.04, 95% C.I. 1.00-1.08). After controlling for age, sex, and tumor grade, racial disparities persisted, with 16% increased risk of dying among blacks relative to whites [adjusted risk ratio 1.16, (99% C.I.) 1.08-1.25, p < 0.001].

CONCLUSION

The cumulative incidence of brain/CNS malignancy is higher among whites relative to that in blacks; however, blacks experienced survival disadvantage even after adjustment for potential tumor prognostic and predisposing factors.

Gender nonconformity of identical twins with discordant sexual orientations: Evidence from childhood photographs

Childhood gender nonconformity (femininity in males, masculinity in females) predicts a nonstraight (gay, lesbian, or bisexual) sexual orientation in adulthood. In previous work, nonstraight twins reported more childhood gender nonconformity than their genetically identical, but straight, cotwins. However, self-reports could be biased. We therefore assessed gender nonconformity via ratings of photographs from childhood and adulthood. These ratings came from independent observers naïve to study hypotheses. Identical twins with discordant sexual orientations (24 male pairs, 32 female pairs) visibly differed in their gender nonconformity from mid-childhood, with higher levels of gender nonconformity observed in the nonstraight twins. This difference was smaller than the analogous difference between identical twins who were concordant straight (4 male pairs, 11 female pairs) and identical twins unrelated to them who were concordant nonstraight (19 male pairs, 8 female pairs). Further, twins in discordant pairs correlated in their observer-rated gender nonconformity. Nongenetic factors likely differentiated the discordant twins' gender-related characteristics in childhood, but shared influences made them similar in some respects. We further tested how recall of past rejection from others related to gender nonconformity. Rejection generally increased with gender nonconformity, but this effect varied by the twins' sexual orientation. (PsycINFO Database Record

Pupil Dilation to Explicit and Non-Explicit Sexual Stimuli

Pupil dilation to explicit sexual stimuli (footage of naked and aroused men or women) can elicit sex and sexual orientation differences in sexual response. If similar patterns were replicated with non-explicit sexual stimuli (footage of dressed men and women), then pupil dilation could be indicative of automatic sexual response in fully noninvasive designs. We examined this in 325 men and women with varied sexual orientations to determine whether dilation patterns to non-explicit sexual stimuli resembled those to explicit sexual stimuli depicting the same sex or other sex. Sexual orientation differences in pupil dilation to non-explicit sexual stimuli mirrored those to explicit sexual stimuli. However, the relationship of dilation to non-explicit sexual stimuli with dilation to corresponding explicit sexual stimuli was modest, and effect magnitudes were smaller with non-explicit sexual stimuli than explicit sexual stimuli. The prediction that sexual orientation differences in pupil dilation are larger in men than in women was confirmed with explicit sexual stimuli but not with non-explicit sexual stimuli.

Experiences of women referred for urgent assessment of postmenopausal bleeding (PMB)

Women with postmenopausal bleeding (PMB) are referred for specialist assessment within 2 weeks of presentation to their GP. No research has previously examined women's experiences of expedited referral. This was investigated in the present study using questionnaires (6-item State Anxiety Inventory (6-STAI)) and focus groups. A total of 55 women completed questionnaires. Results showed high levels of anxiety at first hospital visit (mean 47.0 (SD 14.27); 95% CI 43.14-50.93). Scores declined by 90 days, but were higher in those not undergoing hysteroscopy. Fifteen women who underwent hysteroscopy attended focus groups. Women recalled fear of cancer from symptom onset until receipt of results. Anxiety was exacerbated by poor knowledge of PMB and lack of awareness of expedited referral. Post-discharge, those with unexplained or recurrent symptoms expressed frustration and upset. Effective strategies to raise awareness of PMB and its causes are needed, including reasons for expedited referral. Women without cancer may also need more support.

Energy cost of walking in children with spastic cerebral palsy: relationship with age, body composition and mobility capacity

The energy cost (EC) of walking is different for typically developing (TD) and children with cerebral palsy (CP). The associated factors of EC are not fully understood in children with CP. We assessed the relationship between EC and age, body surface area (BSA), and gross motor function measure (GMFM). We retrospectively examined data collected between 2003 and 2011 on 276 children aged 4-18 years who were classified as Gross Motor Function Classification System level I, n=79; II, n=123; and III, n=74. Energy cost was assessed while children walked 6-8 min at a comfortable, self-selected speed using their typical walking aids and/or orthoses as part of a clinical gait analysis. During the test, participants wore a breath-by-breath portable gas analysis system, measuring oxygen consumption. To calculate EC (J/kg/m), oxygen consumption was converted to J/kg/min and divided by walking speed. Data were analyzed using linear regression model. Energy cost correlated inversely with age (β=-0.16, R2=0.02, P=0.01), BSA (β=-3.35, R2=0.11, P<0.0001), and GMFM (β=-0.12, R2=0.42, P<0.0001). In the multiple linear regression model, GMFM was the most potent correlate of EC, BSA explained another 10% of the variance (R2=0.53), and age was a marginally significant correlate of EC (P=0.08). In summary, in children with CP in our study, EC decreased as GMFM and BSA increased, and GMFM was the most potent correlate of EC.

Racial/Ethnic Variability in Hypertension Prevalence and Risk Factors in National Health Interview Survey

Objective. Hypertension is one of the leading causes of death attributed to cardiovascular diseases, and the prevalence varies across racial/ethnic groups, with African Americans being disproportionately affected. The underlying causes of these disparities are not fully understood despite volume of literature in this perspective. We aimed in this current study to examine ethnic/racial disparities in hypertension utilizing Hispanics as the base racial/ethnic group for comparison. Research Design and Methods. We utilized the National Health Interview Survey (NHIS), which is a large cross-sectional survey of the United States non-institutionalized residents to investigate the racial/ethnic disparities in hypertension after the adjustment of other socio-economic, demographic, and prognostic risk factors. The study participants were adults (n = 30,852). Data were analyzed using Chi square statistic, and logistic regression model. Results. There were statistically significant differences by race/ethnicity with respect to income, education, marital status, smoking, alcohol, physical activities, body mass index, and age, P < 0.01, but not insurance coverage, P > 0.01. Hispanic ethnicity (18.9%) compared to either non-Hispanic white (27.7%) or non-Hispanic black (35.5%) was associated with the lowest prevalence of hypertension. Race/ethnicity was a single independent predictor of hypertension, with non-Hispanic black more likely to be hypertensive compare with Hispanic, prevalence odds ratio (POR), 2.38, 99% Confidence Interval (CI), 2.17–2.61 and non-Hispanic white, POR, 1.64, 99% CI, 1.52–1.77. After controlling for the confounding variables, the racial/ethnic differences in hypertension persisted. Conclusions. Racial/ethnic disparities in hypertension persisted after controlling for potential predictors of hypertension in NHIS, implying the inability of known hypertension risk factors to account for racial/ethnic variability in hypertension in US.

Long-term outcome of reconstruction of the hip in young children with cerebral palsy

We reviewed the long-term radiological outcome, complications and revision operations in 19 children with quadriplegic cerebral palsy and hip dysplasia who underwent combined peri-iliac osteotomy and femoral varus derotation osteotomy. They had a mean age of 7.5 years (1.6 to 10.9) and comprised 22 hip dislocations and subluxations. We also studied the outcome for the contralateral hip. At a mean follow-up of 11.7 years (10 to 15.1) the Melbourne cerebral palsy (CP) hip classification was grade 2 in 16 hips, grade 3 in five, and grade 5 in one. There were five complications seen in four hips (21%, four patients), including one dislocation, one subluxation, one coxa vara with adduction deformity, one subtrochanteric fracture and one infection. A recurrent soft-tissue contracture occurred in five hips and ten required revision surgery.

In pre-adolescent children with quadriplegic cerebral palsy good long-term outcomes can be achieved after reconstruction of the hip; regular follow-up is required.

Cite this article: Bone Joint J 2013;95-B:259–65.

Sex variability in pediatric leukemia survival: large cohort evidence

Purpose. Sex disparities in pediatric leukemia have been previously reported, and male children continue to present with poorer survival. However, the observed disparities are not fully understood. This current study sought to examine disparities in survival by the sex, and to determine if tumor prognostic factors impact on these disparities. Patients and Methods. We used the Surveillance Epidemiology and End Results dataset of pediatric leukemia patients (ages 0–19 years) diagnosed in the United States from 1973 to 2006. There were 15,215 patients of whom 8,622 (65.7%) were boys and 6,593 (43.3%) were girls. The Kaplan-Meier survival estimates, log rank test, and Cox proportional hazard methods were used to assess the data. Results. The overall (both sexes) five-year survival rate was 67.9%. Girls had a survival rate of 70.1%, while the rate was 66.3% in boys. Girls had a significant 14% decreased risk of dying relative to boys, hazard ratio (HR) = 0.86, 99% CI = 0.80–0.93. There were significant differences between boys and girls with respect to tumor cell type, race, age at diagnosis, year of diagnosis, and number of primaries, P < 0.001. After controlling for these factors, the sex differences in survival persisted, with girls still less likely to die from leukemia compared to boys, adjusted HR (AHR) = 0.85, 99% CI = 0.72–1.00, P < 0.01. Conclusion. In a large population-based pediatric leukemia study, boys continued to show poorer survival. These disparities were not completely explained by treatment received, tumor prognostic or socio-demographic factors.

Aspergillus sensitization is associated with airflow limitation and bronchiectasis in severe asthma

BACKGROUND

Abnormalities, including bronchiectasis, that are detectable on high-resolution computed tomography (HRCT) have been associated with severe asthma. Bronchiectasis is associated with the diagnosis of allergic bronchopulmonary aspergillosis (ABPA), which also occurs in patients with severe asthma. We sought to determine the frequency and pattern of HRCT abnormality and the relationship with Aspergillus fumigatus sensitization in one severe asthma population.

METHODS

We examined our database of patients attending a supraregional severe asthma service (Manchester, UK). Clinical, physiological and immunological characteristics were compared between those with HRCT evidence of airway disease (specifically bronchiectasis) and those with no radiological abnormality.

RESULTS

Of 133 patients analysed, 111 (83.4%) had an abnormal HRCT with bronchial wall thickening (41.3%), bronchiectasis (35.3%), air trapping (20.3%) and bronchial dilatation (16.5%) occurring most frequently. Radiological evidence of airway disease was associated with more obstructive spirometry (postbronchodilator FEV₁/FVC ratio 73.2%vs 64.8% [difference -8.5%, 95% CI -16.9 to -0.1, P = 0.048]). A. fumigatus sensitization was associated with a 2.01 increased hazard ratio of bronchiectasis (95% CI 1.26 to 3.22, P = 0.005), and more obstructive spirometry (postbronchodilator FEV₁/FVC ratio 57.6 vs 70.3 [difference -12.8, 95% CI -19.8 to -5.7, P = 0.001]). Patients with A. fumigatus sensitization had variable clinical and radiological characteristics that frequently did not conform to the conventional diagnostic criteria for ABPA.

CONCLUSION

Patients with severe asthma frequently have radiological abnormalities on HRCT. Sensitization to A. fumigatus is associated with bronchiectasis and greater airflow obstruction, even when diagnostic criteria for ABPA are not met.

Occurrence, distribution and characteristics of beached plastic production pellets on the island of Malta (central Mediterranean)

The distribution, abundance and chemical characteristics of plastic production pellets on beaches of the island of Malta have been determined. Pellets were observed at all locations visited and were generally most abundant (> 1000m⁻² at the surface) on the backshores of beaches with a westerly aspect. Most pellets were disc-shaped or flattened cylinders and could be categorised as white, yellow, amber or brown. The polymeric matrix of all pellets analysed by infrared spectroscopy was polyethylene and the degree of yellowing or darkening was associated with an increase in the carbonyl index, hence extent of photo-oxidation or aging. Qualitatively, pellets are similar to those reported for other regions of the Mediterranean in surveys spanning three decades, suggesting that they are a general and persistent characteristic of the region.